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| author | Xiaoyao Li <xiaoyao.li@intel.com> | 2023-10-25 01:59:14 -0400 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2024-02-06 10:59:52 -0800 |
| commit | df01f0a1165c35e95b5f52c7ba25c19020352ff9 (patch) | |
| tree | d7f27ebe55a6970d1775894b30abb45c81ed2555 /Documentation | |
| parent | ccb2280ec2f9e805d70f57a3a1c5deff0d532cb3 (diff) | |
| download | linux-stable-df01f0a1165c35e95b5f52c7ba25c19020352ff9.tar.gz linux-stable-df01f0a1165c35e95b5f52c7ba25c19020352ff9.tar.bz2 linux-stable-df01f0a1165c35e95b5f52c7ba25c19020352ff9.zip | |
KVM: x86: Improve documentation of MSR_KVM_ASYNC_PF_EN
Fix some incorrect statement of MSR_KVM_ASYNC_PF_EN documentation and
state clearly the token in 'struct kvm_vcpu_pv_apf_data' of 'page ready'
event is matchted with the token in CR2 in 'page not present' event.
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20231025055914.1201792-3-xiaoyao.li@intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/virt/kvm/x86/msr.rst | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/Documentation/virt/kvm/x86/msr.rst b/Documentation/virt/kvm/x86/msr.rst index f6d70f99a1a7..3aecf2a70e7b 100644 --- a/Documentation/virt/kvm/x86/msr.rst +++ b/Documentation/virt/kvm/x86/msr.rst @@ -193,8 +193,8 @@ data: 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:: + which must be in guest RAM. This memory is expected to hold the + following structure:: struct kvm_vcpu_pv_apf_data { /* Used for 'page not present' events delivered via #PF */ @@ -231,14 +231,14 @@ data: 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 + Bytes 4-7 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. + of these bytes is a token which was previously delivered in CR2 as + 'page not present' event. The event indicates the page is 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 |