Age | Commit message (Collapse) | Author |
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Now kvm_tdp_mmu_zap_leafs() only zaps leaf SPTEs but not any non-root
pages within that GFN range anymore, so the comment around it isn't
right.
Fix it by shifting the comment from tdp_mmu_zap_leafs() instead of
duplicating it, as tdp_mmu_zap_leafs() is static and is only called by
kvm_tdp_mmu_zap_leafs().
Opportunistically tweak the blurb about SPTEs being cleared to (a) say
"zapped" instead of "cleared" because "cleared" will be wrong if/when
KVM allows a non-zero value for non-present SPTE (i.e. for Intel TDX),
and (b) to clarify that a flush is needed if and only if a SPTE has been
zapped since MMU lock was last acquired.
Fixes: f47e5bbbc92f ("KVM: x86/mmu: Zap only TDP MMU leafs in zap range and mmu_notifier unmap")
Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Message-Id: <20220728030452.484261-1-kai.huang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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As Virtual Machine Save Area (VMSA) is essential in troubleshooting
attestation, dump it to the klog with the KERN_DEBUG level of priority.
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Suggested-by: Harald Hoyer <harald@profian.com>
Signed-off-by: Jarkko Sakkinen <jarkko@profian.com>
Message-Id: <20220728050919.24113-1-jarkko@profian.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Convert the ixgbe PTP frequency adjustment implementations from .adjfreq to
.adjfine. This allows using the scaled parts per million adjustment from
the PTP core and results in a more precise adjustment for small
corrections.
To avoid overflow, use mul_u64_u64_div_u64 to perform the calculation. On
X86 platforms, this will use instructions that perform the operations with
128bit intermediate values. For other architectures, the implementation
will limit the loss of precision as much as possible.
This change slightly improves the precision of frequency adjustments for
all ixgbe based devices, and gets us one driver closer to being able to
remove the older .adjfreq implementation from the kernel.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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The i40e driver currently implements the .adjfreq handler for frequency
adjustments. This takes the adjustment parameter in parts per billion. The
PTP core supports .adjfine which provides an adjustment in scaled parts per
million. This has a higher resolution and can result in more precise
adjustments for small corrections.
Convert the existing .adjfreq implementation to the newer .adjfine
implementation. This is trivial since it just requires changing the divisor
from 1000000000ULL to (1000000ULL << 16) in the mul_u64_u64_div_u64 call.
This improves the precision of the adjustments and gets us one driver
closer to removing the old .adjfreq support from the kernel.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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The i40e device has a different clock rate depending on the current link
speed. This requires using a different increment rate for the PTP clock
registers. For slower link speeds, the base increment value is larger.
Directly multiplying the larger increment value by the parts per billion
adjustment might overflow.
To avoid this, the i40e implementation defaults to using the lower
increment value and then multiplying the adjustment afterwards. This causes
a loss of precision for lower link speeds.
We can fix this by using mul_u64_u64_div_u64 instead of performing the
multiplications using standard C operations. On X86, this will use special
instructions that perform the multiplication and division with 128bit
intermediate values. For other architectures, the fallback implementation
will limit the loss of precision for large values. Small adjustments don't
overflow anyways and won't lose precision at all.
This allows first multiplying the base increment value and then performing
the adjustment calculation, since we no longer fear overflowing. It also
makes it easier to convert to the even more precise .adjfine implementation
in a following change.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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The PTP implementation for the e1000e driver uses the older .adjfreq
method. This method takes an adjustment in parts per billion. The newer
.adjfine implementation uses scaled_ppm. The use of scaled_ppm allows for
finer grained adjustments and is preferred over using the older
implementation.
Make use of mul_u64_u64_div_u64 in order to handle possible overflow of the
multiplication used to calculate the desired adjustment to the hardware
increment value.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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The e1000e_phc_adjfreq function validates that the input delta is within
the maximum range. This is already handled by the core PTP code and this is
a duplicate and thus unnecessary check. It also complicates refactoring to
use the newer .adjfine implementation, where the input is no longer
specified in parts per billion. Remove the range validation check.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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The PTP frequency adjustment code needs to determine an appropriate
adjustment given an input scaled_ppm adjustment.
We calculate the adjustment to the register by multiplying the base
(nominal) increment value by the scaled_ppm and then dividing by the
scaled one million value.
For very large adjustments, this might overflow. To avoid this, both the
scaled_ppm and divisor values are downshifted.
We can avoid that on X86 architectures by using mul_u64_u64_div_u64. This
helper function will perform the multiplication and division with 128bit
intermediate values. We know that scaled_ppm is never larger than the
divisor so this operation will never result in an overflow.
This improves the accuracy of the calculations for large adjustment values
on X86. It is likely an improvement on other architectures as well because
the default implementation of mul_u64_u64_div_u64 is smarter than the
original approach taken in the ice code.
Additionally, this implementation is easier to read, using fewer local
variables and lines of code to implement.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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Treat the NX bit as valid when using NPT, as KVM will set the NX bit when
the NX huge page mitigation is enabled (mindblowing) and trigger the WARN
that fires on reserved SPTE bits being set.
KVM has required NX support for SVM since commit b26a71a1a5b9 ("KVM: SVM:
Refuse to load kvm_amd if NX support is not available") for exactly this
reason, but apparently it never occurred to anyone to actually test NPT
with the mitigation enabled.
------------[ cut here ]------------
spte = 0x800000018a600ee7, level = 2, rsvd bits = 0x800f0000001fe000
WARNING: CPU: 152 PID: 15966 at arch/x86/kvm/mmu/spte.c:215 make_spte+0x327/0x340 [kvm]
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 10.48.0 01/27/2022
RIP: 0010:make_spte+0x327/0x340 [kvm]
Call Trace:
<TASK>
tdp_mmu_map_handle_target_level+0xc3/0x230 [kvm]
kvm_tdp_mmu_map+0x343/0x3b0 [kvm]
direct_page_fault+0x1ae/0x2a0 [kvm]
kvm_tdp_page_fault+0x7d/0x90 [kvm]
kvm_mmu_page_fault+0xfb/0x2e0 [kvm]
npf_interception+0x55/0x90 [kvm_amd]
svm_invoke_exit_handler+0x31/0xf0 [kvm_amd]
svm_handle_exit+0xf6/0x1d0 [kvm_amd]
vcpu_enter_guest+0xb6d/0xee0 [kvm]
? kvm_pmu_trigger_event+0x6d/0x230 [kvm]
vcpu_run+0x65/0x2c0 [kvm]
kvm_arch_vcpu_ioctl_run+0x355/0x610 [kvm]
kvm_vcpu_ioctl+0x551/0x610 [kvm]
__se_sys_ioctl+0x77/0xc0
__x64_sys_ioctl+0x1d/0x20
do_syscall_64+0x44/0xa0
entry_SYSCALL_64_after_hwframe+0x46/0xb0
</TASK>
---[ end trace 0000000000000000 ]---
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220723013029.1753623-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The commit 5413bcba7ed5 ("KVM: x86: Add support for vICR APIC-write
VM-Exits in x2APIC mode") introduces logic to prevent APIC write
for offset other than ICR in kvm_apic_write_nodecode() function.
This breaks x2AVIC support, which requires KVM to trap and emulate
x2APIC MSR writes.
Therefore, removes the warning and modify to logic to allow MSR write.
Fixes: 5413bcba7ed5 ("KVM: x86: Add support for vICR APIC-write VM-Exits in x2APIC mode")
Cc: Zeng Guang <guang.zeng@intel.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Message-Id: <20220725053356.4275-1-suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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AMD does not support APIC TSC-deadline timer mode. AVIC hardware
will generate GP fault when guest kernel writes 1 to bits [18]
of the APIC LVTT register (offset 0x32) to set the timer mode.
(Note: bit 18 is reserved on AMD system).
Therefore, always intercept and let KVM emulate the MSR accesses.
Fixes: f3d7c8aa6882 ("KVM: SVM: Fix x2APIC MSRs interception")
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Message-Id: <20220725033428.3699-1-suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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If mediatek_dwmac_clks_config() fails, then call stmmac_remove_config_dt()
before returning. Otherwise it is a resource leak.
Fixes: fa4b3ca60e80 ("stmmac: dwmac-mediatek: fix clock issue")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YuJ4aZyMUlG6yGGa@kili
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Change net device's MTU to smaller than IPV6_MIN_MTU or unregister
device while matching route. That may trigger null-ptr-deref bug
for ip6_ptr probability as following.
=========================================================
BUG: KASAN: null-ptr-deref in find_match.part.0+0x70/0x134
Read of size 4 at addr 0000000000000308 by task ping6/263
CPU: 2 PID: 263 Comm: ping6 Not tainted 5.19.0-rc7+ #14
Call trace:
dump_backtrace+0x1a8/0x230
show_stack+0x20/0x70
dump_stack_lvl+0x68/0x84
print_report+0xc4/0x120
kasan_report+0x84/0x120
__asan_load4+0x94/0xd0
find_match.part.0+0x70/0x134
__find_rr_leaf+0x408/0x470
fib6_table_lookup+0x264/0x540
ip6_pol_route+0xf4/0x260
ip6_pol_route_output+0x58/0x70
fib6_rule_lookup+0x1a8/0x330
ip6_route_output_flags_noref+0xd8/0x1a0
ip6_route_output_flags+0x58/0x160
ip6_dst_lookup_tail+0x5b4/0x85c
ip6_dst_lookup_flow+0x98/0x120
rawv6_sendmsg+0x49c/0xc70
inet_sendmsg+0x68/0x94
Reproducer as following:
Firstly, prepare conditions:
$ip netns add ns1
$ip netns add ns2
$ip link add veth1 type veth peer name veth2
$ip link set veth1 netns ns1
$ip link set veth2 netns ns2
$ip netns exec ns1 ip -6 addr add 2001:0db8:0:f101::1/64 dev veth1
$ip netns exec ns2 ip -6 addr add 2001:0db8:0:f101::2/64 dev veth2
$ip netns exec ns1 ifconfig veth1 up
$ip netns exec ns2 ifconfig veth2 up
$ip netns exec ns1 ip -6 route add 2000::/64 dev veth1 metric 1
$ip netns exec ns2 ip -6 route add 2001::/64 dev veth2 metric 1
Secondly, execute the following two commands in two ssh windows
respectively:
$ip netns exec ns1 sh
$while true; do ip -6 addr add 2001:0db8:0:f101::1/64 dev veth1; ip -6 route add 2000::/64 dev veth1 metric 1; ping6 2000::2; done
$ip netns exec ns1 sh
$while true; do ip link set veth1 mtu 1000; ip link set veth1 mtu 1500; sleep 5; done
It is because ip6_ptr has been assigned to NULL in addrconf_ifdown() firstly,
then ip6_ignore_linkdown() accesses ip6_ptr directly without NULL check.
cpu0 cpu1
fib6_table_lookup
__find_rr_leaf
addrconf_notify [ NETDEV_CHANGEMTU ]
addrconf_ifdown
RCU_INIT_POINTER(dev->ip6_ptr, NULL)
find_match
ip6_ignore_linkdown
So we can add NULL check for ip6_ptr before using in ip6_ignore_linkdown() to
fix the null-ptr-deref bug.
Fixes: dcd1f572954f ("net/ipv6: Remove fib6_idev")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220728013307.656257-1-william.xuanziyang@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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When we close ping6 sockets, some resources are left unfreed because
pingv6_prot is missing sk->sk_prot->destroy(). As reported by
syzbot [0], just three syscalls leak 96 bytes and easily cause OOM.
struct ipv6_sr_hdr *hdr;
char data[24] = {0};
int fd;
hdr = (struct ipv6_sr_hdr *)data;
hdr->hdrlen = 2;
hdr->type = IPV6_SRCRT_TYPE_4;
fd = socket(AF_INET6, SOCK_DGRAM, NEXTHDR_ICMP);
setsockopt(fd, IPPROTO_IPV6, IPV6_RTHDR, data, 24);
close(fd);
To fix memory leaks, let's add a destroy function.
Note the socket() syscall checks if the GID is within the range of
net.ipv4.ping_group_range. The default value is [1, 0] so that no
GID meets the condition (1 <= GID <= 0). Thus, the local DoS does
not succeed until we change the default value. However, at least
Ubuntu/Fedora/RHEL loosen it.
$ cat /usr/lib/sysctl.d/50-default.conf
...
-net.ipv4.ping_group_range = 0 2147483647
Also, there could be another path reported with these options, and
some of them require CAP_NET_RAW.
setsockopt
IPV6_ADDRFORM (inet6_sk(sk)->pktoptions)
IPV6_RECVPATHMTU (inet6_sk(sk)->rxpmtu)
IPV6_HOPOPTS (inet6_sk(sk)->opt)
IPV6_RTHDRDSTOPTS (inet6_sk(sk)->opt)
IPV6_RTHDR (inet6_sk(sk)->opt)
IPV6_DSTOPTS (inet6_sk(sk)->opt)
IPV6_2292PKTOPTIONS (inet6_sk(sk)->opt)
getsockopt
IPV6_FLOWLABEL_MGR (inet6_sk(sk)->ipv6_fl_list)
For the record, I left a different splat with syzbot's one.
unreferenced object 0xffff888006270c60 (size 96):
comm "repro2", pid 231, jiffies 4294696626 (age 13.118s)
hex dump (first 32 bytes):
01 00 00 00 44 00 00 00 00 00 00 00 00 00 00 00 ....D...........
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000f6bc7ea9>] sock_kmalloc (net/core/sock.c:2564 net/core/sock.c:2554)
[<000000006d699550>] do_ipv6_setsockopt.constprop.0 (net/ipv6/ipv6_sockglue.c:715)
[<00000000c3c3b1f5>] ipv6_setsockopt (net/ipv6/ipv6_sockglue.c:1024)
[<000000007096a025>] __sys_setsockopt (net/socket.c:2254)
[<000000003a8ff47b>] __x64_sys_setsockopt (net/socket.c:2265 net/socket.c:2262 net/socket.c:2262)
[<000000007c409dcb>] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
[<00000000e939c4a9>] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
[0]: https://syzkaller.appspot.com/bug?extid=a8430774139ec3ab7176
Fixes: 6d0bfe226116 ("net: ipv6: Add IPv6 support to the ping socket.")
Reported-by: syzbot+a8430774139ec3ab7176@syzkaller.appspotmail.com
Reported-by: Ayushman Dutta <ayudutta@amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220728012220.46918-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The cgroup_update_dfl_csses() function updates css associations when a
cgroup's subtree_control file is modified. Any changes made to a cgroup's
subtree_control file, however, will only affect its descendants but not
the cgroup itself. So there is no point in migrating csses associated
with that cgroup. We can skip them instead.
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Verify that KVM allows toggling VMX MSR bits to be "more" restrictive,
and also allows restoring each MSR to KVM's original, less restrictive
value.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-16-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Make UMIP an "allowed-1" bit CR4_FIXED1 MSR when KVM is emulating UMIP.
KVM emulates UMIP for both L1 and L2, and so should enumerate that L2 is
allowed to have CR4.UMIP=1. Not setting the bit doesn't immediately
break nVMX, as KVM does set/clear the bit in CR4_FIXED1 in response to a
guest CPUID update, i.e. KVM will correctly (dis)allow nested VM-Entry
based on whether or not UMIP is exposed to L1. That said, KVM should
enumerate the bit as being allowed from time zero, e.g. userspace will
see the wrong value if the MSR is read before CPUID is written.
Fixes: 0367f205a3b7 ("KVM: vmx: add support for emulating UMIP")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-12-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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This reverts commit 03a8871add95213827e2bea84c12133ae5df952e.
Since commit 03a8871add95 ("KVM: nVMX: Expose load IA32_PERF_GLOBAL_CTRL
VM-{Entry,Exit} control"), KVM has taken ownership of the "load
IA32_PERF_GLOBAL_CTRL" VMX entry/exit control bits, trying to set these
bits in the IA32_VMX_TRUE_{ENTRY,EXIT}_CTLS MSRs if the guest's CPUID
supports the architectural PMU (CPUID[EAX=0Ah].EAX[7:0]=1), and clear
otherwise.
This was a misguided attempt at mimicking what commit 5f76f6f5ff96
("KVM: nVMX: Do not expose MPX VMX controls when guest MPX disabled",
2018-10-01) did for MPX. However, that commit was a workaround for
another KVM bug and not something that should be imitated. Mucking with
the VMX MSRs creates a subtle, difficult to maintain ABI as KVM must
ensure that any internal changes, e.g. to how KVM handles _any_ guest
CPUID changes, yield the same functional result. Therefore, KVM's policy
is to let userspace have full control of the guest vCPU model so long
as the host kernel is not at risk.
Now that KVM really truly ensures kvm_set_msr() will succeed by loading
PERF_GLOBAL_CTRL if and only if it exists, revert KVM's misguided and
roundabout behavior.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[sean: make it a pure revert]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220722224409.1336532-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Attempt to load PERF_GLOBAL_CTRL during nested VM-Enter/VM-Exit if and
only if the MSR exists (according to the guest vCPU model). KVM has very
misguided handling of VM_{ENTRY,EXIT}_LOAD_IA32_PERF_GLOBAL_CTRL and
attempts to force the nVMX MSR settings to match the vPMU model, i.e. to
hide/expose the control based on whether or not the MSR exists from the
guest's perspective.
KVM's modifications fail to handle the scenario where the vPMU is hidden
from the guest _after_ being exposed to the guest, e.g. by userspace
doing multiple KVM_SET_CPUID2 calls, which is allowed if done before any
KVM_RUN. nested_vmx_pmu_refresh() is called if and only if there's a
recognized vPMU, i.e. KVM will leave the bits in the allow state and then
ultimately reject the MSR load and WARN.
KVM should not force the VMX MSRs in the first place. KVM taking control
of the MSRs was a misguided attempt at mimicking what commit 5f76f6f5ff96
("KVM: nVMX: Do not expose MPX VMX controls when guest MPX disabled",
2018-10-01) did for MPX. However, the MPX commit was a workaround for
another KVM bug and not something that should be imitated (and it should
never been done in the first place).
In other words, KVM's ABI _should_ be that userspace has full control
over the MSRs, at which point triggering the WARN that loading the MSR
must not fail is trivial.
The intent of the WARN is still valid; KVM has consistency checks to
ensure that vmcs12->{guest,host}_ia32_perf_global_ctrl is valid. The
problem is that '0' must be considered a valid value at all times, and so
the simple/obvious solution is to just not actually load the MSR when it
does not exist. It is userspace's responsibility to provide a sane vCPU
model, i.e. KVM is well within its ABI and Intel's VMX architecture to
skip the loads if the MSR does not exist.
Fixes: 03a8871add95 ("KVM: nVMX: Expose load IA32_PERF_GLOBAL_CTRL VM-{Entry,Exit} control")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220722224409.1336532-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Add a helper to check of the guest PMU has PERF_GLOBAL_CTRL, which is
unintuitive _and_ diverges from Intel's architecturally defined behavior.
Even worse, KVM currently implements the check using two different (but
equivalent) checks, _and_ there has been at least one attempt to add a
_third_ flavor.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220722224409.1336532-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Mark all MSR_CORE_PERF_GLOBAL_CTRL and MSR_CORE_PERF_GLOBAL_OVF_CTRL bits
as reserved if there is no guest vPMU. The nVMX VM-Entry consistency
checks do not check for a valid vPMU prior to consuming the masks via
kvm_valid_perf_global_ctrl(), i.e. may incorrectly allow a non-zero mask
to be loaded via VM-Enter or VM-Exit (well, attempted to be loaded, the
actual MSR load will be rejected by intel_is_valid_msr()).
Fixes: f5132b01386b ("KVM: Expose a version 2 architectural PMU to a guests")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220722224409.1336532-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Since commit 5f76f6f5ff96 ("KVM: nVMX: Do not expose MPX VMX controls
when guest MPX disabled"), KVM has taken ownership of the "load
IA32_BNDCFGS" and "clear IA32_BNDCFGS" VMX entry/exit controls,
trying to set these bits in the IA32_VMX_TRUE_{ENTRY,EXIT}_CTLS
MSRs if the guest's CPUID supports MPX, and clear otherwise.
The intent of the patch was to apply it to L0 in order to work around
L1 kernels that lack the fix in commit 691bd4340bef ("kvm: vmx: allow
host to access guest MSR_IA32_BNDCFGS", 2017-07-04): by hiding the
control bits from L0, L1 hides BNDCFGS from KVM_GET_MSR_INDEX_LIST,
and the L1 bug is neutralized even in the lack of commit 691bd4340bef.
This was perhaps a sensible kludge at the time, but a horrible
idea in the long term and in fact it has not been extended to
other CPUID bits like these:
X86_FEATURE_LM => VM_EXIT_HOST_ADDR_SPACE_SIZE, VM_ENTRY_IA32E_MODE,
VMX_MISC_SAVE_EFER_LMA
X86_FEATURE_TSC => CPU_BASED_RDTSC_EXITING, CPU_BASED_USE_TSC_OFFSETTING,
SECONDARY_EXEC_TSC_SCALING
X86_FEATURE_INVPCID_SINGLE => SECONDARY_EXEC_ENABLE_INVPCID
X86_FEATURE_MWAIT => CPU_BASED_MONITOR_EXITING, CPU_BASED_MWAIT_EXITING
X86_FEATURE_INTEL_PT => SECONDARY_EXEC_PT_CONCEAL_VMX, SECONDARY_EXEC_PT_USE_GPA,
VM_EXIT_CLEAR_IA32_RTIT_CTL, VM_ENTRY_LOAD_IA32_RTIT_CTL
X86_FEATURE_XSAVES => SECONDARY_EXEC_XSAVES
These days it's sort of common knowledge that any MSR in
KVM_GET_MSR_INDEX_LIST must allow *at least* setting it with KVM_SET_MSR
to a default value, so it is unlikely that something like commit
5f76f6f5ff96 will be needed again. So revert it, at the potential cost
of breaking L1s with a 6 year old kernel. While in principle the L0 owner
doesn't control what runs on L1, such an old hypervisor would probably
have many other bugs.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Restrict the nVMX MSRs based on KVM's config, not based on the guest's
current config. Using the guest's config to audit the new config
prevents userspace from restoring the original config (KVM's config) if
at any point in the past the guest's config was restricted in any way.
Fixes: 62cc6b9dc61e ("KVM: nVMX: support restore of VMX capability MSRs")
Cc: stable@vger.kernel.org
Cc: David Matlack <dmatlack@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Rename the exit handlers for VMXON and VMXOFF to match the instruction
names, the terms "vmon" and "vmoff" are not used anywhere in Intel's
documentation, nor are they used elsehwere in KVM.
Sadly, the exit reasons are exposed to userspace and so cannot be renamed
without breaking userspace. :-(
Fixes: ec378aeef9df ("KVM: nVMX: Implement VMXON and VMXOFF")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Inject a #UD if L1 attempts VMXON with a CR0 or CR4 that is disallowed
per the associated nested VMX MSRs' fixed0/1 settings. KVM cannot rely
on hardware to perform the checks, even for the few checks that have
higher priority than VM-Exit, as (a) KVM may have forced CR0/CR4 bits in
hardware while running the guest, (b) there may incompatible CR0/CR4 bits
that have lower priority than VM-Exit, e.g. CR0.NE, and (c) userspace may
have further restricted the allowed CR0/CR4 values by manipulating the
guest's nested VMX MSRs.
Note, despite a very strong desire to throw shade at Jim, commit
70f3aac964ae ("kvm: nVMX: Remove superfluous VMX instruction fault checks")
is not to blame for the buggy behavior (though the comment...). That
commit only removed the CR0.PE, EFLAGS.VM, and COMPATIBILITY mode checks
(though it did erroneously drop the CPL check, but that has already been
remedied). KVM may force CR0.PE=1, but will do so only when also
forcing EFLAGS.VM=1 to emulate Real Mode, i.e. hardware will still #UD.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216033
Fixes: ec378aeef9df ("KVM: nVMX: Implement VMXON and VMXOFF")
Reported-by: Eric Li <ercli@ucdavis.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Check that the guest (L2) and host (L1) CR4 values that would be loaded
by nested VM-Enter and VM-Exit respectively are valid with respect to
KVM's (L0 host) allowed CR4 bits. Failure to check KVM reserved bits
would allow L1 to load an illegal CR4 (or trigger hardware VM-Fail or
failed VM-Entry) by massaging guest CPUID to allow features that are not
supported by KVM. Amusingly, KVM itself is an accomplice in its doom, as
KVM adjusts L1's MSR_IA32_VMX_CR4_FIXED1 to allow L1 to enable bits for
L2 based on L1's CPUID model.
Note, although nested_{guest,host}_cr4_valid() are _currently_ used if
and only if the vCPU is post-VMXON (nested.vmxon == true), that may not
be true in the future, e.g. emulating VMXON has a bug where it doesn't
check the allowed/required CR0/CR4 bits.
Cc: stable@vger.kernel.org
Fixes: 3899152ccbf4 ("KVM: nVMX: fix checks on CR{0,4} during virtual VMX operation")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Split the common x86 parts of kvm_is_valid_cr4(), i.e. the reserved bits
checks, into a separate helper, __kvm_is_valid_cr4(), and export only the
inner helper to vendor code in order to prevent nested VMX from calling
back into vmx_is_valid_cr4() via kvm_is_valid_cr4().
On SVM, this is a nop as SVM doesn't place any additional restrictions on
CR4.
On VMX, this is also currently a nop, but only because nested VMX is
missing checks on reserved CR4 bits for nested VM-Enter. That bug will
be fixed in a future patch, and could simply use kvm_is_valid_cr4() as-is,
but nVMX has _another_ bug where VMXON emulation doesn't enforce VMX's
restrictions on CR0/CR4. The cleanest and most intuitive way to fix the
VMXON bug is to use nested_host_cr{0,4}_valid(). If the CR4 variant
routes through kvm_is_valid_cr4(), using nested_host_cr4_valid() won't do
the right thing for the VMXON case as vmx_is_valid_cr4() enforces VMX's
restrictions if and only if the vCPU is post-VMXON.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Add a command line option to dirty_log_perf_test to run vCPUs for the
entire duration of disabling dirty logging. By default, the test stops
running runs vCPUs before disabling dirty logging, which is faster but
less interesting as it doesn't stress KVM's handling of contention
between page faults and the zapping of collapsible SPTEs. Enabling the
flag also lets the user verify that KVM is indeed rebuilding zapped SPTEs
as huge pages by checking KVM's pages_{1g,2m,4k} stats. Without vCPUs to
fault in the zapped SPTEs, the stats will show that KVM is zapping pages,
but they never show whether or not KVM actually allows huge pages to be
recreated.
Note! Enabling the flag can _significantly_ increase runtime, especially
if the thread that's disabling dirty logging doesn't have a dedicated
pCPU, e.g. if all pCPUs are used to run vCPUs.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220715232107.3775620-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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When zapping collapsible SPTEs in the TDP MMU, don't bottom out on a leaf
SPTE now that KVM doesn't require a PFN to compute the host mapping level,
i.e. now that there's no need to first find a leaf SPTE and then step
back up.
Drop the now unused tdp_iter_step_up(), as it is not the safest of
helpers (using any of the low level iterators requires some understanding
of the various side effects).
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220715232107.3775620-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Add a comment to document how host_pfn_mapping_level() can be used safely,
as the line between safe and dangerous is quite thin. E.g. if KVM were
to ever support in-place promotion to create huge pages, consuming the
level is safe if the caller holds mmu_lock and checks that there's an
existing _leaf_ SPTE, but unsafe if the caller only checks that there's a
non-leaf SPTE.
Opportunistically tweak the existing comments to explicitly document why
KVM needs to use READ_ONCE().
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220715232107.3775620-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Drop the requirement that a pfn be backed by a refcounted, compound or
or ZONE_DEVICE, struct page, and instead rely solely on the host page
tables to identify huge pages. The PageCompound() check is a remnant of
an old implementation that identified (well, attempt to identify) huge
pages without walking the host page tables. The ZONE_DEVICE check was
added as an exception to the PageCompound() requirement. In other words,
neither check is actually a hard requirement, if the primary has a pfn
backed with a huge page, then KVM can back the pfn with a huge page
regardless of the backing store.
Dropping the @pfn parameter will also allow KVM to query the max host
mapping level without having to first get the pfn, which is advantageous
for use outside of the page fault path where KVM wants to take action if
and only if a page can be mapped huge, i.e. avoids the pfn lookup for
gfns that can't be backed with a huge page.
Cc: Mingwei Zhang <mizhang@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Mingwei Zhang <mizhang@google.com>
Message-Id: <20220715232107.3775620-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Restrict the mapping level for SPTEs based on the guest MTRRs if and only
if KVM may actually use the guest MTRRs to compute the "real" memtype.
For all forms of paging, guest MTRRs are purely virtual in the sense that
they are completely ignored by hardware, i.e. they affect the memtype
only if software manually consumes them. The only scenario where KVM
consumes the guest MTRRs is when shadow_memtype_mask is non-zero and the
guest has non-coherent DMA, in all other cases KVM simply leaves the PAT
field in SPTEs as '0' to encode WB memtype.
Note, KVM may still ultimately ignore guest MTRRs, e.g. if the backing
pfn is host MMIO, but false positives are ok as they only cause a slight
performance blip (unless the guest is doing weird things with its MTRRs,
which is extremely unlikely).
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220715230016.3762909-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Add shadow_memtype_mask to capture that EPT needs a non-zero memtype mask
instead of relying on TDP being enabled, as NPT doesn't need a non-zero
mask. This is a glorified nop as kvm_x86_ops.get_mt_mask() returns zero
for NPT anyways.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220715230016.3762909-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Return directly if kvm_arch_init() detects an error before doing any real
work, jumping through a label obfuscates what's happening and carries the
unnecessary risk of leaving 'r' uninitialized.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220715230016.3762909-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Reject KVM if entry '0' in the host's IA32_PAT MSR is not programmed to
writeback (WB) memtype. KVM subtly relies on IA32_PAT entry '0' to be
programmed to WB by leaving the PAT bits in shadow paging and NPT SPTEs
as '0'. If something other than WB is in PAT[0], at _best_ guests will
suffer very poor performance, and at worst KVM will crash the system by
breaking cache-coherency expecations (e.g. using WC for guest memory).
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220715230016.3762909-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The index for svm_direct_access_msrs was incorrectly initialized with
the APIC MMIO register macros. Fix by introducing a macro for calculating
x2APIC MSRs.
Fixes: 5c127c85472c ("KVM: SVM: Adding support for configuring x2APIC MSRs interception")
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Message-Id: <20220718083833.222117-1-suravee.suthikulpanit@amd.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Remove the underscores from __pte_list_remove(), the function formerly
known as pte_list_remove() is now named kvm_zap_one_rmap_spte() to show
that it zaps rmaps/PTEs, i.e. doesn't just remove an entry from a list.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220715224226.3749507-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Rename pte_list_remove() and pte_list_destroy() to kvm_zap_one_rmap_spte()
and kvm_zap_all_rmap_sptes() respectively to document that (a) they zap
SPTEs and (b) to better document how they differ (remove vs. destroy does
not exactly scream "one vs. all").
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220715224226.3749507-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Rename kvm_unmap_rmap() and kvm_zap_rmap() to kvm_zap_rmap() and
__kvm_zap_rmap() respectively to show that what was the "unmap" helper is
just a wrapper for the "zap" helper, i.e. that they do the exact same
thing, one just exists to deal with its caller passing in more params.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220715224226.3749507-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Rename __kvm_zap_rmaps() to kvm_rmap_zap_gfn_range() to avoid future
confusion with a soon-to-be-introduced __kvm_zap_rmap(). Using a plural
"rmaps" is somewhat ambiguous without additional context, as it's not
obvious whether it's referring to multiple rmap lists, versus multiple
rmap entries within a single list.
Use kvm_rmap_zap_gfn_range() to align with the pattern established by
kvm_rmap_zap_collapsible_sptes(), without losing the information that it
zaps only rmap-based MMUs, i.e. don't rename it to __kvm_zap_gfn_range().
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220715224226.3749507-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Drop the trailing "p" from rmap helpers, i.e. rename functions to simply
be kvm_<action>_rmap(). Declaring that a function takes a pointer is
completely unnecessary and goes against kernel style.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220715224226.3749507-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Use pte_list_destroy() directly when recycling rmaps instead of bouncing
through kvm_unmap_rmapp() and kvm_zap_rmapp(). Calling kvm_unmap_rmapp()
is unnecessary and odd as it requires passing dummy parameters; passing
NULL for @slot when __rmap_add() already has a valid slot is especially
weird and confusing.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220715224226.3749507-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Return a u64, not an int, from mmu_spte_clear_track_bits(). The return
value is the old SPTE value, which is very much a 64-bit value. The sole
caller that consumes the return value, drop_spte(), already uses a u64.
The only reason that truncating the SPTE value is not problematic is
because drop_spte() only queries the shadow-present bit, which is in the
lower 32 bits.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220715224226.3749507-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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enter_svm_guest_mode() first calls nested_vmcb02_prepare_control() to copy
control fields from VMCB12 to the current VMCB, then
nested_vmcb02_prepare_save() to perform a similar copy of the save area.
This means that nested_vmcb02_prepare_control() still runs with the
previous save area values in the current VMCB so it shouldn't take the L2
guest CS.Base from this area.
Explicitly pull CS.Base from the actual VMCB12 instead in
enter_svm_guest_mode().
Granted, having a non-zero CS.Base is a very rare thing (and even
impossible in 64-bit mode), having it change between nested VMRUNs is
probably even rarer, but if it happens it would create a really subtle bug
so it's better to fix it upfront.
Fixes: 6ef88d6e36c2 ("KVM: SVM: Re-inject INT3/INTO instead of retrying the instruction")
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <4caa0f67589ae3c22c311ee0e6139496902f2edc.1658159083.git.maciej.szmigiero@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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If a watch is being added to a queue, it needs to guard against
interference from addition of a new watch, manual removal of a watch and
removal of a watch due to some other queue being destroyed.
KEYCTL_WATCH_KEY guards against this for the same {key,queue} pair by
holding the key->sem writelocked and by holding refs on both the key and
the queue - but that doesn't prevent interaction from other {key,queue}
pairs.
While add_watch_to_object() does take the spinlock on the event queue,
it doesn't take the lock on the source's watch list. The assumption was
that the caller would prevent that (say by taking key->sem) - but that
doesn't prevent interference from the destruction of another queue.
Fix this by locking the watcher list in add_watch_to_object().
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Reported-by: syzbot+03d7b43290037d1f87ca@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
cc: keyrings@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Since __post_watch_notification() walks wlist->watchers with only the
RCU read lock held, we need to use RCU methods to add to the list (we
already use RCU methods to remove from the list).
Fix add_watch_to_object() to use hlist_add_head_rcu() instead of
hlist_add_head() for that list.
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This fixes the paths of x86 / arm efi-stub source files.
Signed-off-by: João Paulo Rechi Vita <jprvita@endlessos.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220727140539.10021-1-jprvita@endlessos.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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Update to commit 6c757e9f55f0 ("docs/scheduler:
fix unit error")
ddb21d27a6a5 ("docs/scheduler: Change unit of
cpu_time and rq_time to nanoseconds")
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Wu XiangCheng <bobwxc@email.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/3cb1c4c466dfa38d72a867dc6e2c833ceb69ecb7.1658983157.git.siyanteng@loongson.cn
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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Update to commit f21949c14968 ("PCI/doc:Update
obsolete pci_set_dma_mask() references")
05b0ebd06ae6 ("PCI/doc: cleanup references to
the legacy PCI DMA API")
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Wu XiangCheng <bobwxc@email.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/bccb98a1c6706ecfd4aaba8c27f1c64024e1c139.1658983157.git.siyanteng@loongson.cn
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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Update to commit 4f23bd5d09af ("PCI/doc: Convert
examples to generic power management")
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/24c53aabc9d942f6fe38b8d3a843329edca3d18c.1658983157.git.siyanteng@loongson.cn
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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