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authorLinus Torvalds <torvalds@linux-foundation.org>2020-06-03 15:13:47 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-03 15:13:47 -0700
commit039aeb9deb9291f3b19c375a8bc6fa7f768996cc (patch)
treed98d5ddf276843995aa214157b587bb88270c530 /Documentation
parent6b2591c21273ebf65c13dae5d260ce88f0f197dd (diff)
parent13ffbd8db1dd43d63d086517872a4e702a6bf309 (diff)
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini: "ARM: - Move the arch-specific code into arch/arm64/kvm - Start the post-32bit cleanup - Cherry-pick a few non-invasive pre-NV patches x86: - Rework of TLB flushing - Rework of event injection, especially with respect to nested virtualization - Nested AMD event injection facelift, building on the rework of generic code and fixing a lot of corner cases - Nested AMD live migration support - Optimization for TSC deadline MSR writes and IPIs - Various cleanups - Asynchronous page fault cleanups (from tglx, common topic branch with tip tree) - Interrupt-based delivery of asynchronous "page ready" events (host side) - Hyper-V MSRs and hypercalls for guest debugging - VMX preemption timer fixes s390: - Cleanups Generic: - switch vCPU thread wakeup from swait to rcuwait The other architectures, and the guest side of the asynchronous page fault work, will come next week" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (256 commits) KVM: selftests: fix rdtsc() for vmx_tsc_adjust_test KVM: check userspace_addr for all memslots KVM: selftests: update hyperv_cpuid with SynDBG tests x86/kvm/hyper-v: Add support for synthetic debugger via hypercalls x86/kvm/hyper-v: enable hypercalls regardless of hypercall page x86/kvm/hyper-v: Add support for synthetic debugger interface x86/hyper-v: Add synthetic debugger definitions KVM: selftests: VMX preemption timer migration test KVM: nVMX: Fix VMX preemption timer migration x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit KVM: x86/pmu: Support full width counting KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT KVM: x86: acknowledgment mechanism for async pf page ready notifications KVM: x86: interrupt based APF 'page ready' event delivery KVM: introduce kvm_read_guest_offset_cached() KVM: rename kvm_arch_can_inject_async_page_present() to kvm_arch_can_dequeue_async_page_present() KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info Revert "KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously" KVM: VMX: Replace zero-length array with flexible-array ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/virt/kvm/api.rst41
-rw-r--r--Documentation/virt/kvm/cpuid.rst8
-rw-r--r--Documentation/virt/kvm/msr.rst119
-rw-r--r--Documentation/virt/kvm/nested-vmx.rst5
4 files changed, 136 insertions, 37 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index d2c1cbce1018..426f94582b7a 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -4336,9 +4336,13 @@ Errors:
#define KVM_STATE_NESTED_VMX_SMM_GUEST_MODE 0x00000001
#define KVM_STATE_NESTED_VMX_SMM_VMXON 0x00000002
+#define KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE 0x00000001
+
struct kvm_vmx_nested_state_hdr {
+ __u32 flags;
__u64 vmxon_pa;
__u64 vmcs12_pa;
+ __u64 preemption_timer_deadline;
struct {
__u16 flags;
@@ -5068,10 +5072,13 @@ EOI was received.
struct kvm_hyperv_exit {
#define KVM_EXIT_HYPERV_SYNIC 1
#define KVM_EXIT_HYPERV_HCALL 2
+ #define KVM_EXIT_HYPERV_SYNDBG 3
__u32 type;
+ __u32 pad1;
union {
struct {
__u32 msr;
+ __u32 pad2;
__u64 control;
__u64 evt_page;
__u64 msg_page;
@@ -5081,6 +5088,15 @@ EOI was received.
__u64 result;
__u64 params[2];
} hcall;
+ struct {
+ __u32 msr;
+ __u32 pad2;
+ __u64 control;
+ __u64 status;
+ __u64 send_page;
+ __u64 recv_page;
+ __u64 pending_page;
+ } syndbg;
} u;
};
/* KVM_EXIT_HYPERV */
@@ -5097,6 +5113,12 @@ Hyper-V SynIC state change. Notification is used to remap SynIC
event/message pages and to enable/disable SynIC messages/events processing
in userspace.
+ - KVM_EXIT_HYPERV_SYNDBG -- synchronously notify user-space about
+
+Hyper-V Synthetic debugger state change. Notification is used to either update
+the pending_page location or to send a control command (send the buffer located
+in send_page or recv a buffer to recv_page).
+
::
/* KVM_EXIT_ARM_NISV */
@@ -5779,7 +5801,7 @@ will be initialized to 1 when created. This also improves performance because
dirty logging can be enabled gradually in small chunks on the first call
to KVM_CLEAR_DIRTY_LOG. KVM_DIRTY_LOG_INITIALLY_SET depends on
KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (it is also only available on
-x86 for now).
+x86 and arm64 for now).
KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 was previously available under the name
KVM_CAP_MANUAL_DIRTY_LOG_PROTECT, but the implementation had bugs that make
@@ -5804,6 +5826,23 @@ If present, this capability can be enabled for a VM, meaning that KVM
will allow the transition to secure guest mode. Otherwise KVM will
veto the transition.
+7.20 KVM_CAP_HALT_POLL
+----------------------
+
+:Architectures: all
+:Target: VM
+:Parameters: args[0] is the maximum poll time in nanoseconds
+:Returns: 0 on success; -1 on error
+
+This capability overrides the kvm module parameter halt_poll_ns for the
+target VM.
+
+VCPU polling allows a VCPU to poll for wakeup events instead of immediately
+scheduling during guest halts. The maximum time a VCPU can spend polling is
+controlled by the kvm module parameter halt_poll_ns. This capability allows
+the maximum halt time to specified on a per-VM basis, effectively overriding
+the module parameter for the target VM.
+
8. Other capabilities.
======================
diff --git a/Documentation/virt/kvm/cpuid.rst b/Documentation/virt/kvm/cpuid.rst
index 01b081f6e7ea..a7dff9186bed 100644
--- a/Documentation/virt/kvm/cpuid.rst
+++ b/Documentation/virt/kvm/cpuid.rst
@@ -50,8 +50,8 @@ KVM_FEATURE_NOP_IO_DELAY 1 not necessary to perform delays
KVM_FEATURE_MMU_OP 2 deprecated
KVM_FEATURE_CLOCKSOURCE2 3 kvmclock available at msrs
-
0x4b564d00 and 0x4b564d01
+
KVM_FEATURE_ASYNC_PF 4 async pf can be enabled by
writing to msr 0x4b564d02
@@ -86,6 +86,12 @@ KVM_FEATURE_PV_SCHED_YIELD 13 guest checks this feature bit
before using paravirtualized
sched yield.
+KVM_FEATURE_ASYNC_PF_INT 14 guest checks this feature bit
+ before using the second async
+ pf control msr 0x4b564d06 and
+ async pf acknowledgment msr
+ 0x4b564d07.
+
KVM_FEATURE_CLOCSOURCE_STABLE_BIT 24 host will warn if no guest-side
per-cpu warps are expeced in
kvmclock
diff --git a/Documentation/virt/kvm/msr.rst b/Documentation/virt/kvm/msr.rst
index 33892036672d..e37a14c323d2 100644
--- a/Documentation/virt/kvm/msr.rst
+++ b/Documentation/virt/kvm/msr.rst
@@ -190,41 +190,72 @@ MSR_KVM_ASYNC_PF_EN:
0x4b564d02
data:
- Bits 63-6 hold 64-byte aligned physical address of a
- 64 byte memory area which must be in guest RAM and must be
- zeroed. Bits 5-3 are reserved and should be zero. Bit 0 is 1
- when asynchronous page faults are enabled on the vcpu 0 when
- disabled. Bit 1 is 1 if asynchronous page faults can be injected
- when vcpu is in cpl == 0. Bit 2 is 1 if asynchronous page faults
- are delivered to L1 as #PF vmexits. Bit 2 can be set only if
- KVM_FEATURE_ASYNC_PF_VMEXIT is present in CPUID.
-
- First 4 byte of 64 byte memory location will be written to by
- the hypervisor at the time of asynchronous page fault (APF)
- injection to indicate type of asynchronous page fault. Value
- of 1 means that the page referred to by the page fault is not
- present. Value 2 means that the page is now available. Disabling
- interrupt inhibits APFs. Guest must not enable interrupt
- before the reason is read, or it may be overwritten by another
- APF. Since APF uses the same exception vector as regular page
- fault guest must reset the reason to 0 before it does
- something that can generate normal page fault. If during page
- fault APF reason is 0 it means that this is regular page
- fault.
-
- During delivery of type 1 APF cr2 contains a token that will
- be used to notify a guest when missing page becomes
- available. When page becomes available type 2 APF is sent with
- cr2 set to the token associated with the page. There is special
- kind of token 0xffffffff which tells vcpu that it should wake
- up all processes waiting for APFs and no individual type 2 APFs
- will be sent.
+ Asynchronous page fault (APF) control MSR.
+
+ Bits 63-6 hold 64-byte aligned physical address of a 64 byte memory area
+ which must be in guest RAM and must be zeroed. This memory is expected
+ to hold a copy of the following structure::
+
+ struct kvm_vcpu_pv_apf_data {
+ /* Used for 'page not present' events delivered via #PF */
+ __u32 flags;
+
+ /* Used for 'page ready' events delivered via interrupt notification */
+ __u32 token;
+
+ __u8 pad[56];
+ __u32 enabled;
+ };
+
+ Bits 5-4 of the MSR are reserved and should be zero. Bit 0 is set to 1
+ when asynchronous page faults are enabled on the vcpu, 0 when disabled.
+ Bit 1 is 1 if asynchronous page faults can be injected when vcpu is in
+ cpl == 0. Bit 2 is 1 if asynchronous page faults are delivered to L1 as
+ #PF vmexits. Bit 2 can be set only if KVM_FEATURE_ASYNC_PF_VMEXIT is
+ present in CPUID. Bit 3 enables interrupt based delivery of 'page ready'
+ events. Bit 3 can only be set if KVM_FEATURE_ASYNC_PF_INT is present in
+ CPUID.
+
+ 'Page not present' events are currently always delivered as synthetic
+ #PF exception. During delivery of these events APF CR2 register contains
+ a token that will be used to notify the guest when missing page becomes
+ available. Also, to make it possible to distinguish between real #PF and
+ APF, first 4 bytes of 64 byte memory location ('flags') will be written
+ to by the hypervisor at the time of injection. Only first bit of 'flags'
+ is currently supported, when set, it indicates that the guest is dealing
+ with asynchronous 'page not present' event. If during a page fault APF
+ 'flags' is '0' it means that this is regular page fault. Guest is
+ supposed to clear 'flags' when it is done handling #PF exception so the
+ next event can be delivered.
+
+ Note, since APF 'page not present' events use the same exception vector
+ as regular page fault, guest must reset 'flags' to '0' before it does
+ something that can generate normal page fault.
+
+ Bytes 5-7 of 64 byte memory location ('token') will be written to by the
+ hypervisor at the time of APF 'page ready' event injection. The content
+ of these bytes is a token which was previously delivered as 'page not
+ present' event. The event indicates the page in now available. Guest is
+ supposed to write '0' to 'token' when it is done handling 'page ready'
+ event and to write 1' to MSR_KVM_ASYNC_PF_ACK after clearing the location;
+ writing to the MSR forces KVM to re-scan its queue and deliver the next
+ pending notification.
+
+ Note, MSR_KVM_ASYNC_PF_INT MSR specifying the interrupt vector for 'page
+ ready' APF delivery needs to be written to before enabling APF mechanism
+ in MSR_KVM_ASYNC_PF_EN or interrupt #0 can get injected. The MSR is
+ available if KVM_FEATURE_ASYNC_PF_INT is present in CPUID.
+
+ Note, previously, 'page ready' events were delivered via the same #PF
+ exception as 'page not present' events but this is now deprecated. If
+ bit 3 (interrupt based delivery) is not set APF events are not delivered.
If APF is disabled while there are outstanding APFs, they will
not be delivered.
- Currently type 2 APF will be always delivered on the same vcpu as
- type 1 was, but guest should not rely on that.
+ Currently 'page ready' APF events will be always delivered on the
+ same vcpu as 'page not present' event was, but guest should not rely on
+ that.
MSR_KVM_STEAL_TIME:
0x4b564d03
@@ -319,3 +350,29 @@ data:
KVM guests can request the host not to poll on HLT, for example if
they are performing polling themselves.
+
+MSR_KVM_ASYNC_PF_INT:
+ 0x4b564d06
+
+data:
+ Second asynchronous page fault (APF) control MSR.
+
+ Bits 0-7: APIC vector for delivery of 'page ready' APF events.
+ Bits 8-63: Reserved
+
+ Interrupt vector for asynchnonous 'page ready' notifications delivery.
+ The vector has to be set up before asynchronous page fault mechanism
+ is enabled in MSR_KVM_ASYNC_PF_EN. The MSR is only available if
+ KVM_FEATURE_ASYNC_PF_INT is present in CPUID.
+
+MSR_KVM_ASYNC_PF_ACK:
+ 0x4b564d07
+
+data:
+ Asynchronous page fault (APF) acknowledgment.
+
+ When the guest is done processing 'page ready' APF event and 'token'
+ field in 'struct kvm_vcpu_pv_apf_data' is cleared it is supposed to
+ write '1' to bit 0 of the MSR, this causes the host to re-scan its queue
+ and check if there are more notifications pending. The MSR is available
+ if KVM_FEATURE_ASYNC_PF_INT is present in CPUID.
diff --git a/Documentation/virt/kvm/nested-vmx.rst b/Documentation/virt/kvm/nested-vmx.rst
index 592b0ab6970b..89851cbb7df9 100644
--- a/Documentation/virt/kvm/nested-vmx.rst
+++ b/Documentation/virt/kvm/nested-vmx.rst
@@ -116,10 +116,7 @@ struct shadow_vmcs is ever changed.
natural_width cr4_guest_host_mask;
natural_width cr0_read_shadow;
natural_width cr4_read_shadow;
- natural_width cr3_target_value0;
- natural_width cr3_target_value1;
- natural_width cr3_target_value2;
- natural_width cr3_target_value3;
+ natural_width dead_space[4]; /* Last remnants of cr3_target_value[0-3]. */
natural_width exit_qualification;
natural_width guest_linear_address;
natural_width guest_cr0;