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Now that the core code does not use this monstrosity anymore, it's time to
put it to rest.
The only real purpose was to read the APIC ID on UV and VSMP systems for
the actual evaluation. That's what the core code does now.
For doing the actual shift operation there is truly no APIC callback
required.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20240212153625.516536121@linutronix.de
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No more users.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20240212153625.455839743@linutronix.de
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Now that everything is converted switch it over and remove the intermediate
operation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20240212153625.334185785@linutronix.de
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cpuinfo::topo::x86_coreid_bits is about to be phased out. Use the core
domain size from the topology information.
Add a comment why the early MPTABLE parsing is required and decrapify the
loop which sets the APIC ID to node map.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20240212153625.270320718@linutronix.de
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Switch it over to the new topology evaluation mechanism and remove the
random bits and pieces which are sprinkled all over the place.
No functional change intended.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20240212153625.145745053@linutronix.de
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AMD/HYGON uses various methods for topology evaluation:
- Leaf 0x80000008 and 0x8000001e based with an optional leaf 0xb,
which is the preferred variant for modern CPUs.
Leaf 0xb will be superseded by leaf 0x80000026 soon, which is just
another variant of the Intel 0x1f leaf for whatever reasons.
- Subleaf 0x80000008 and NODEID_MSR base
- Legacy fallback
That code is following the principle of random bits and pieces all over the
place which results in multiple evaluations and impenetrable code flows in
the same way as the Intel parsing did.
Provide a sane implementation by clearly separating the three variants and
bringing them in the proper preference order in one place.
This provides the parsing for both AMD and HYGON because there is no point
in having a separate HYGON parser which only differs by 3 lines of
code. Any further divergence between AMD and HYGON can be handled in
different functions, while still sharing the existing parsers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20240212153625.020038641@linutronix.de
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AMD (ab)uses topology_die_id() to store the Node ID information and
topology_max_dies_per_pkg to store the number of nodes per package.
This collides with the proper processor die level enumeration which is
coming on AMD with CPUID 8000_0026, unless there is a correlation between
the two. There is zero documentation about that.
So provide new storage and new accessors which for now still access die_id
and topology_max_die_per_pkg(). Will be mopped up after AMD and HYGON are
converted over.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20240212153624.956116738@linutronix.de
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Topology evaluation is a complete disaster and impenetrable mess. It's
scattered all over the place with some vendor implementations doing early
evaluation and some not. The most horrific part is the permanent
overwriting of smt_max_siblings and __max_die_per_package, instead of
establishing them once on the boot CPU and validating the result on the
APs.
The goals are:
- One topology evaluation entry point
- Proper sharing of pointlessly duplicated code
- Proper structuring of the evaluation logic and preferences.
- Evaluating important system wide information only once on the boot CPU
- Making the 0xb/0x1f leaf parsing less convoluted and actually fixing
the short comings of leaf 0x1f evaluation.
Start to consolidate the topology evaluation code by providing the entry
points for the early boot CPU evaluation and for the final parsing on the
boot CPU and the APs.
Move the trivial pieces into that new code:
- The initialization of cpuinfo_x86::topo
- The evaluation of CPUID leaf 1, which presets topo::initial_apicid
- topo_apicid is set to topo::initial_apicid when invoked from early
boot. When invoked for the final evaluation on the boot CPU it reads
the actual APIC ID, which makes apic_get_initial_apicid() obsolete
once everything is converted over.
Provide a temporary helper function topo_converted() which shields off the
not yet converted CPU vendors from invoking code which would break them.
This shielding covers all vendor CPUs which support SMP, but not the
historical pure UP ones as they only need the topology info init and
eventually the initial APIC initialization.
Provide two new members in cpuinfo_x86::topo to store the maximum number of
SMT siblings and the number of dies per package and add them to the debugfs
readout. These two members will be used to populate this information on the
boot CPU and to validate the APs against it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240212153624.581436579@linutronix.de
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Provide a few helper functions to read CPUID leafs or individual registers
into a data structure without requiring unions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/878r3mg570.ffs@tglx
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dependent patches
Merge in pending alternatives patching infrastructure changes, before
applying more patches.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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branch
Conflicts:
arch/x86/include/asm/percpu.h
arch/x86/include/asm/text-patching.h
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Make sure the default return thunk is not used after all return
instructions have been patched by the alternatives because the default
return thunk is insufficient when it comes to mitigating Retbleed or
SRSO.
Fix based on an earlier version by David Kaplan <david.kaplan@amd.com>.
[ bp: Fix the compilation error of warn_thunk_thunk being an invisible
symbol, hoist thunk macro into calling.h ]
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Co-developed-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231010171020.462211-4-david.kaplan@amd.com
Link: https://lore.kernel.org/r/20240104132446.GEZZaxnrIgIyat0pqf@fat_crate.local
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We've had issues with gcc and 'asm goto' before, and we created a
'asm_volatile_goto()' macro for that in the past: see commits
3f0116c3238a ("compiler/gcc4: Add quirk for 'asm goto' miscompilation
bug") and a9f180345f53 ("compiler/gcc4: Make quirk for
asm_volatile_goto() unconditional").
Then, much later, we ended up removing the workaround in commit
43c249ea0b1e ("compiler-gcc.h: remove ancient workaround for gcc PR
58670") because we no longer supported building the kernel with the
affected gcc versions, but we left the macro uses around.
Now, Sean Christopherson reports a new version of a very similar
problem, which is fixed by re-applying that ancient workaround. But the
problem in question is limited to only the 'asm goto with outputs'
cases, so instead of re-introducing the old workaround as-is, let's
rename and limit the workaround to just that much less common case.
It looks like there are at least two separate issues that all hit in
this area:
(a) some versions of gcc don't mark the asm goto as 'volatile' when it
has outputs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420
which is easy to work around by just adding the 'volatile' by hand.
(b) Internal compiler errors:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422
which are worked around by adding the extra empty 'asm' as a
barrier, as in the original workaround.
but the problem Sean sees may be a third thing since it involves bad
code generation (not an ICE) even with the manually added 'volatile'.
but the same old workaround works for this case, even if this feels a
bit like voodoo programming and may only be hiding the issue.
Reported-and-tested-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Andrew Pinski <quic_apinski@quicinc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Cleanups to Kconfig definitions for KVM
* replace HAVE_KVM with an architecture-dependent symbol, when CONFIG_KVM
may or may not be available depending on CPU capabilities (MIPS)
* replace HAVE_KVM with IS_ENABLED(CONFIG_KVM) for host-side code that is
not part of the KVM module, so that it is completely compiled out
* factor common "select" statements in common code instead of requiring
each architecture to specify it
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It is more accurate to check if KVM is enabled, instead of having the
architecture say so. Architectures always "have" KVM, so for example
checking CONFIG_HAVE_KVM in x86 code is pointless, but if KVM is disabled
in a specific build, there is no need for support code.
Alternatively, many of the #ifdefs could simply be deleted. However,
this would add completely dead code. For example, when KVM is disabled,
there should not be any posted interrupts, i.e. NOT wiring up the "dummy"
handlers and treating IRQs on those vectors as spurious is the right
thing to do.
Cc: x86@kernel.org
Cc: kbingham@kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Since all architectures (for historical reasons) have to define
struct kvm_guest_debug_arch, and since userspace has to check
KVM_CHECK_EXTENSION(KVM_CAP_SET_GUEST_DEBUG) anyway, there is
no advantage in masking the capability #define itself. Remove
the #define __KVM_HAVE_GUEST_DEBUG from architecture-specific
headers.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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KVM uses __KVM_HAVE_* symbols in the architecture-dependent uapi/asm/kvm.h to mask
unused definitions in include/uapi/linux/kvm.h. __KVM_HAVE_READONLY_MEM however
was nothing but a misguided attempt to define KVM_CAP_READONLY_MEM only on
architectures where KVM_CHECK_EXTENSION(KVM_CAP_READONLY_MEM) could possibly
return nonzero. This however does not make sense, and it prevented userspace
from supporting this architecture-independent feature without recompilation.
Therefore, these days __KVM_HAVE_READONLY_MEM does not mask anything and
is only used in virt/kvm/kvm_main.c. Userspace does not need to test it
and there should be no need for it to exist. Remove it and replace it
with a Kconfig symbol within Linux source code.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Several capabilities that exist only on x86 nevertheless have their
structs defined in include/uapi/linux/kvm.h. Move them to
arch/x86/include/uapi/asm/kvm.h for cleanliness.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Change uapi header uses of GENMASK to instead use the uapi/linux/bits.h bit
macros, since GENMASK is not defined in uapi headers.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Change uapi header uses of BIT to instead use the uapi/linux/const.h bit
macros, since BIT is not defined in uapi headers.
The PMU mask uses _BITUL since it targets a 32 bit flag field, whereas
the longmode definition is meant for a 64 bit flag field.
Cc: Sean Christophersen <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Dionna Glaze <dionnaglaze@google.com>
Message-Id: <20231207001142.3617856-1-dionnaglaze@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Pull kvm fixes from Paolo Bonzini:
"x86 guest:
- Avoid false positive for check that only matters on AMD processors
x86:
- Give a hint when Win2016 might fail to boot due to XSAVES &&
!XSAVEC configuration
- Do not allow creating an in-kernel PIT unless an IOAPIC already
exists
RISC-V:
- Allow ISA extensions that were enabled for bare metal in 6.8 (Zbc,
scalar and vector crypto, Zfh[min], Zihintntl, Zvfh[min], Zfa)
S390:
- fix CC for successful PQAP instruction
- fix a race when creating a shadow page"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
x86/coco: Define cc_vendor without CONFIG_ARCH_HAS_CC_PLATFORM
x86/kvm: Fix SEV check in sev_map_percpu_data()
KVM: x86: Give a hint when Win2016 might fail to boot due to XSAVES erratum
KVM: x86: Check irqchip mode before create PIT
KVM: riscv: selftests: Add Zfa extension to get-reg-list test
RISC-V: KVM: Allow Zfa extension for Guest/VM
KVM: riscv: selftests: Add Zvfh[min] extensions to get-reg-list test
RISC-V: KVM: Allow Zvfh[min] extensions for Guest/VM
KVM: riscv: selftests: Add Zihintntl extension to get-reg-list test
RISC-V: KVM: Allow Zihintntl extension for Guest/VM
KVM: riscv: selftests: Add Zfh[min] extensions to get-reg-list test
RISC-V: KVM: Allow Zfh[min] extensions for Guest/VM
KVM: riscv: selftests: Add vector crypto extensions to get-reg-list test
RISC-V: KVM: Allow vector crypto extensions for Guest/VM
KVM: riscv: selftests: Add scaler crypto extensions to get-reg-list test
RISC-V: KVM: Allow scalar crypto extensions for Guest/VM
KVM: riscv: selftests: Add Zbc extension to get-reg-list test
RISC-V: KVM: Allow Zbc extension for Guest/VM
KVM: s390: fix cc for successful PQAP
KVM: s390: vsie: fix race during shadow creation
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The KVM PTP driver now refers to the clocksource ID CSID_X86_KVM_CLK, not
to the clocksource itself any more. There are no remaining users of the
clocksource export.
Therefore, make the clocksource static again.
Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240201010453.2212371-9-peter.hilber@opensynergy.com
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Refer to commit fd10cde9294f ("KVM paravirt: Add async PF initialization
to PV guest") and commit 344d9588a9df ("KVM: Add PV MSR to enable
asynchronous page faults delivery"). It turns out that at the time when
asyncpf was introduced, the purpose was defining the shared PV data 'struct
kvm_vcpu_pv_apf_data' with the size of 64 bytes. However, it made a mistake
and defined the size to 68 bytes, which failed to make fit in a cache line
and made the code inconsistent with the documentation.
Below justification quoted from Sean[*]
KVM (the host side) has *never* read kvm_vcpu_pv_apf_data.enabled, and
the documentation clearly states that enabling is based solely on the
bit in the synthetic MSR.
So rather than update the documentation, fix the goof by removing the
enabled filed and use the separate percpu variable instread.
KVM-as-a-host obviously doesn't enforce anything or consume the size,
and changing the header will only affect guests that are rebuilt against
the new header, so there's no chance of ABI breakage between KVM and its
guests. The only possible breakage is if some other hypervisor is
emulating KVM's async #PF (LOL) and relies on the guest to set
kvm_vcpu_pv_apf_data.enabled. But (a) I highly doubt such a hypervisor
exists, (b) that would arguably be a violation of KVM's "spec", and
(c) the worst case scenario is that the guest would simply lose async
#PF functionality.
[*] https://lore.kernel.org/all/ZS7ERnnRqs8Fl0ZF@google.com/T/#u
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20231025055914.1201792-2-xiaoyao.li@intel.com
[sean: use true/false instead of 1/0 for booleans]
Signed-off-by: Sean Christopherson <seanjc@google.com>
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The early startup code executes from a 1:1 mapping of memory, which
differs from the mapping that the code was linked and/or relocated to
run at. The latter mapping is not active yet at this point, and so
symbol references that rely on it will fault.
Given that the core kernel is built without -fPIC, symbol references are
typically emitted as absolute, and so any such references occuring in
the early startup code will therefore crash the kernel.
While an attempt was made to work around this for the early SEV/SME
startup code, by forcing RIP-relative addressing for certain global
SEV/SME variables via inline assembly (see snp_cpuid_get_table() for
example), RIP-relative addressing must be pervasively enforced for
SEV/SME global variables when accessed prior to page table fixups.
__startup_64() already handles this issue for select non-SEV/SME global
variables using fixup_pointer(), which adjusts the pointer relative to a
`physaddr` argument. To avoid having to pass around this `physaddr`
argument across all functions needing to apply pointer fixups, introduce
a macro RIP_RELATIVE_REF() which generates a RIP-relative reference to
a given global variable. It is used where necessary to force
RIP-relative accesses to global variables.
For backporting purposes, this patch makes no attempt at cleaning up
other occurrences of this pattern, involving either inline asm or
fixup_pointer(). Those will be addressed later.
[ bp: Call it "rip_rel_ref" everywhere like other code shortens
"rIP-relative reference" and make the asm wrapper __always_inline. ]
Co-developed-by: Kevin Loughlin <kevinloughlin@google.com>
Signed-off-by: Kevin Loughlin <kevinloughlin@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/all/20240130220845.1978329-1-kevinloughlin@google.com
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After commit a9ef277488cf ("x86/kvm: Fix SEV check in
sev_map_percpu_data()"), there is a build error when building
x86_64_defconfig with GCOV using LLVM:
ld.lld: error: undefined symbol: cc_vendor
>>> referenced by kvm.c
>>> arch/x86/kernel/kvm.o:(kvm_smp_prepare_boot_cpu) in archive vmlinux.a
which corresponds to
if (cc_vendor != CC_VENDOR_AMD ||
!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
return;
Without GCOV, clang is able to eliminate the use of cc_vendor because
cc_platform_has() evaluates to false when CONFIG_ARCH_HAS_CC_PLATFORM is
not set, meaning that if statement will be true no matter what value
cc_vendor has.
With GCOV, the instrumentation keeps the use of cc_vendor around for
code coverage purposes but cc_vendor is only declared, not defined,
without CONFIG_ARCH_HAS_CC_PLATFORM, leading to the build error above.
Provide a macro definition of cc_vendor when CONFIG_ARCH_HAS_CC_PLATFORM
is not set with a value of CC_VENDOR_NONE, so that the first condition
can always be evaluated/eliminated at compile time, avoiding the build
error altogether. This is very similar to the situation prior to
commit da86eb961184 ("x86/coco: Get rid of accessor functions").
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Message-Id: <20240202-provide-cc_vendor-without-arch_has_cc_platform-v1-1-09ad5f2a3099@kernel.org>
Fixes: a9ef277488cf ("x86/kvm: Fix SEV check in sev_map_percpu_data()", 2024-01-31)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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inline properly
Change array_index_mask_nospec() to __always_inline because "inline" is
broken as https://www.kernel.org/doc/local/inline.html.
Fixes: 6786137bf8fd ("x86/fred: FRED entry/exit and dispatch code")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240202090225.322544-1-xin@zytor.com
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This patch creates wordpart.h and includes it in asm/word-at-a-time.h
for all architectures. WORD_AT_A_TIME_CONSTANTS depends on kernel.h
because of REPEAT_BYTE. Moving this to another header and including it
where necessary allows us to not include the bloated kernel.h. Making
this implicit dependency on REPEAT_BYTE explicit allows for later
improvements in the lib/string.c inclusion list.
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Tanzir Hasan <tanzirh@google.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20231226-libstringheader-v6-1-80aa08c7652c@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>
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Refactor the handling of the reprogramming bitmap to snapshot and clear
to-be-processed bits before doing the reprogramming, and then explicitly
set bits for PMCs that need to be reprogrammed (again). This will allow
adding a macro to iterate over all valid PMCs without having to add
special handling for the reprogramming bit, which (a) can have bits set
for non-existent PMCs and (b) needs to clear such bits to avoid wasting
cycles in perpetuity.
Note, the existing behavior of clearing bits after reprogramming does NOT
have a race with kvm_vm_ioctl_set_pmu_event_filter(). Setting a new PMU
filter synchronizes SRCU _before_ setting the bitmap, i.e. guarantees that
the vCPU isn't in the middle of reprogramming with a stale filter prior to
setting the bitmap.
Link: https://lore.kernel.org/r/20231110022857.1273836-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Add a common helper for *internal* PMC lookups, and delete the ops hook
and Intel's implementation. Keep AMD's implementation, but rename it to
amd_pmu_get_pmc() to make it somewhat more obvious that it's suited for
both KVM-internal and guest-initiated lookups.
Because KVM tracks all counters in a single bitmap, getting a counter
when iterating over a bitmap, e.g. of all valid PMCs, requires a small
amount of math, that while simple, isn't super obvious and doesn't use the
same semantics as PMC lookups from RDPMC! Although AMD doesn't support
fixed counters, the common PMU code still behaves as if there a split, the
high half of which just happens to always be empty.
Opportunstically add a comment to explain both what is going on, and why
KVM uses a single bitmap, e.g. the boilerplate for iterating over separate
bitmaps could be done via macros, so it's not (just) about deduplicating
code.
Link: https://lore.kernel.org/r/20231110022857.1273836-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Since commit b0563468eeac ("x86/CPU/AMD: Disable XSAVES on AMD family 0x17")
kernel unconditionally clears the XSAVES CPU feature bit on Zen1/2 CPUs.
Because KVM CPU caps are initialized from the kernel boot CPU features this
makes the XSAVES feature also unavailable for KVM guests in this case.
At the same time the XSAVEC feature is left enabled.
Unfortunately, having XSAVEC but no XSAVES in CPUID breaks Hyper-V enabled
Windows Server 2016 VMs that have more than one vCPU.
Let's at least give users hint in the kernel log what could be wrong since
these VMs currently simply hang at boot with a black screen - giving no
clue what suddenly broke them and how to make them work again.
Trigger the kernel message hint based on the particular guest ID written to
the Guest OS Identity Hyper-V MSR implemented by KVM.
Defer this check to when the L1 Hyper-V hypervisor enables SVM in EFER
since we want to limit this message to Hyper-V enabled Windows guests only
(Windows session running nested as L2) but the actual Guest OS Identity MSR
write is done by L1 and happens before it enables SVM.
Fixes: b0563468eeac ("x86/CPU/AMD: Disable XSAVES on AMD family 0x17")
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <b83ab45c5e239e5d148b0ae7750133a67ac9575c.1706127425.git.maciej.szmigiero@oracle.com>
[Move some checks before mutex_lock(), rename function. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Add cpu_init_fred_exceptions() to:
- Set FRED entrypoints for events happening in ring 0 and 3.
- Specify the stack level for IRQs occurred ring 0.
- Specify dedicated event stacks for #DB/NMI/#MCE/#DF.
- Enable FRED and invalidtes IDT.
- Force 32-bit system calls to use "int $0x80" only.
Add fred_complete_exception_setup() to:
- Initialize system_vectors as done for IDT systems.
- Set unused sysvec_table entries to fred_handle_spurious_interrupt().
Co-developed-by: Xin Li <xin3.li@intel.com>
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-35-xin3.li@intel.com
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In IRQ/NMI induced VM exits, KVM VMX needs to execute the respective
handlers, which requires the software to create a FRED stack frame,
and use it to invoke the handlers. Add fred_irq_entry_from_kvm() for
this job.
Export fred_entry_from_kvm() because VMX can be compiled as a module.
Suggested-by: Sean Christopherson <seanjc@google.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-32-xin3.li@intel.com
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If the stack frame contains an invalid user context (e.g. due to invalid SS,
a non-canonical RIP, etc.) the ERETU instruction will trap (#SS or #GP).
From a Linux point of view, this really should be considered a user space
failure, so use the standard fault fixup mechanism to intercept the fault,
fix up the exception frame, and redirect execution to fred_entrypoint_user.
The end result is that it appears just as if the hardware had taken the
exception immediately after completing the transition to user space.
Suggested-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-30-xin3.li@intel.com
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Add sysvec_install() to install a system interrupt handler into the IDT
or the FRED system interrupt handler table.
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-28-xin3.li@intel.com
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The code to actually handle kernel and event entry/exit using
FRED. It is split up into two files thus:
- entry_64_fred.S contains the actual entrypoints and exit code, and
saves and restores registers.
- entry_fred.c contains the two-level event dispatch code for FRED.
The first-level dispatch is on the event type, and the second-level
is on the event vector.
[ bp: Fold in an allmodconfig clang build fix:
https://lore.kernel.org/r/20240129064521.5168-1-xin3.li@intel.com
and a CONFIG_IA32_EMULATION=n build fix:
https://lore.kernel.org/r/20240127093728.1323-3-xin3.li@intel.com]
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Originally-by: Megha Dey <megha.dey@intel.com>
Co-developed-by: Xin Li <xin3.li@intel.com>
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231209214214.2932-1-xin3.li@intel.com
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FRED and IDT can share most of the definitions and declarations so
that in the majority of cases the actual handler implementation is the
same.
The differences are the exceptions where FRED stores exception related
information on the stack and the sysvec implementations as FRED can
handle irqentry/exit() in the dispatcher instead of having it in each
handler.
Also add stub defines for vectors which are not used due to Kconfig
decisions to spare the ifdeffery in the actual FRED dispatch code.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-23-xin3.li@intel.com
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MSR_IA32_FRED_RSP0 is used during ring 3 event delivery, and needs to
be updated to point to the top of next task stack during task switch.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-18-xin3.li@intel.com
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When using FRED, reserve space at the top of the stack frame, just
like i386 does.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-17-xin3.li@intel.com
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Add a header file for FRED prototypes and definitions.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-16-xin3.li@intel.com
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FRED defines additional information in the upper 48 bits of cs/ss
fields. Therefore add the information definitions into the pt_regs
structure.
Specifically introduce a new structure fred_ss to denote the FRED flags
above SS selector, which avoids FRED_SSX_ macros and makes the code
simpler and easier to read.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Originally-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-15-xin3.li@intel.com
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struct pt_regs is hard to read because the member or section related
comments are not aligned with the members.
The 'cs' and 'ss' members of pt_regs are type of 'unsigned long' while
in reality they are only 16-bit wide. This works so far as the
remaining space is unused, but FRED will use the remaining bits for
other purposes.
To prepare for FRED:
- Cleanup the formatting
- Convert 'cs' and 'ss' to u16 and embed them into an union
with a u64
- Fixup the related printk() format strings
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Originally-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-14-xin3.li@intel.com
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Add MSR numbers for the FRED configuration registers per FRED spec 5.0.
Originally-by: Megha Dey <megha.dey@intel.com>
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-13-xin3.li@intel.com
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Add X86_CR4_FRED macro for the FRED bit in %cr4. This bit must not be
changed after initialization, so add it to the pinned CR4 bits.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-12-xin3.li@intel.com
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Apply the pre-intercepts RDPMC validity check only to AMD, and rename all
relevant functions to make it as clear as possible that the check is not a
standard PMC index check. On Intel, the basic rule is that only invalid
opcodes and privilege/permission/mode checks have priority over VM-Exit,
i.e. RDPMC with an invalid index should VM-Exit, not #GP. While the SDM
doesn't explicitly call out RDPMC, it _does_ explicitly use RDMSR of a
non-existent MSR as an example where VM-Exit has priority over #GP, and
RDPMC is effectively just a variation of RDMSR.
Manually testing on various Intel CPUs confirms this behavior, and the
inverted priority was introduced for SVM compatibility, i.e. was not an
intentional change for Intel PMUs. On AMD, *all* exceptions on RDPMC have
priority over VM-Exit.
Check for a NULL kvm_pmu_ops.check_rdpmc_early instead of using a RET0
static call so as to provide a convenient location to document the
difference between Intel and AMD, and to again try to make it as obvious
as possible that the early check is a one-off thing, not a generic "is
this PMC valid?" helper.
Fixes: 8061252ee0d2 ("KVM: SVM: Add intercept checks for remaining twobyte instructions")
Cc: Jim Mattson <jmattson@google.com>
Tested-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://lore.kernel.org/r/20240109230250.424295-8-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Remove KVM's bogus restriction that the guest can't program an event whose
encoding matches an unsupported architectural event. The enumeration of
an architectural event only says that if a CPU supports an architectural
event, then the event can be programmed using the architectural encoding.
The enumeration does NOT say anything about the encoding when the CPU
doesn't report support the architectural event.
Preventing the guest from counting events whose encoding happens to match
an architectural event breaks existing functionality whenever Intel adds
an architectural encoding that was *ever* used for a CPU that doesn't
enumerate support for the architectural event, even if the encoding is for
the exact same event!
E.g. the architectural encoding for Top-Down Slots is 0x01a4. Broadwell
CPUs, which do not support the Top-Down Slots architectural event, 0x01a4
is a valid, model-specific event. Denying guest usage of 0x01a4 if/when
KVM adds support for Top-Down slots would break any Broadwell-based guest.
Reported-by: Kan Liang <kan.liang@linux.intel.com>
Closes: https://lore.kernel.org/all/2004baa6-b494-462c-a11f-8104ea152c6a@linux.intel.com
Fixes: a21864486f7e ("KVM: x86/pmu: Fix available_event_types check for REF_CPU_CYCLES event")
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://lore.kernel.org/r/20240109230250.424295-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Remove the include statement for <asm/bootparam.h> from several files
that don't require it and limit the exposure of those definitions within
the Linux kernel code.
[ bp: Massage commit message. ]
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240112095000.8952-5-tzimmermann@suse.de
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The x86 implementation of arch_ima_efi_boot_mode() uses the global
boot_param state. Move it into a source file to clean up the header.
Avoid potential rebuilds of unrelated source files if boot_params
changes.
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240112095000.8952-4-tzimmermann@suse.de
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Move struct_efi_setup_data in order to unify duplicated definition of
the data structure in a single place. Also silence clang's warnings
about GNU extensions in real-mode code which might occur from the
changed includes.
[ bp: Massage commit message. ]
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240112095000.8952-3-tzimmermann@suse.de
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The type definition of struct pci_setup_rom in <asm/pci.h> requires
struct setup_data from <asm/bootparam.h>. Many drivers include
<linux/pci.h>, but do not use boot parameters. Changes to bootparam.h or
its included header files could easily trigger a large, unnecessary
rebuild of the kernel.
Moving struct setup_data and related code into its own header file
avoids including <asm/bootparam.h> in <asm/pci.h>. Instead include the
new header <asm/screen_data.h> and remove the include statement for
x86_init.h, which is unnecessary but pulls in bootparams.h.
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240112095000.8952-2-tzimmermann@suse.de
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"22 hotfixes. 11 are cc:stable and the remainder address post-6.7
issues or aren't considered appropriate for backporting"
* tag 'mm-hotfixes-stable-2024-01-28-23-21' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (22 commits)
mm: thp_get_unmapped_area must honour topdown preference
mm: huge_memory: don't force huge page alignment on 32 bit
userfaultfd: fix mmap_changing checking in mfill_atomic_hugetlb
selftests/mm: ksm_tests should only MADV_HUGEPAGE valid memory
scs: add CONFIG_MMU dependency for vfree_atomic()
mm/memory: fix folio_set_dirty() vs. folio_mark_dirty() in zap_pte_range()
mm/huge_memory: fix folio_set_dirty() vs. folio_mark_dirty()
selftests/mm: Update va_high_addr_switch.sh to check CPU for la57 flag
selftests: mm: fix map_hugetlb failure on 64K page size systems
MAINTAINERS: supplement of zswap maintainers update
stackdepot: make fast paths lock-less again
stackdepot: add stats counters exported via debugfs
mm, kmsan: fix infinite recursion due to RCU critical section
mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again
selftests/mm: switch to bash from sh
MAINTAINERS: add man-pages git trees
mm: memcontrol: don't throttle dying tasks on memory.high
mm: mmap: map MAP_STACK to VM_NOHUGEPAGE
uprobes: use pagesize-aligned virtual address when replacing pages
selftests/mm: mremap_test: fix build warning
...
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