| Message ID | 20240228024147.41573-4-seanjc@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86/mmu: Page fault and MMIO cleanups | expand |
On 2/27/24 18:41, Sean Christopherson wrote: > Define more #NPF error code flags that are relevant to SEV+ (mostly SNP) > guests, as specified by the APM: > > * Bit 34 (ENC): Set to 1 if the guest’s effective C-bit was 1, 0 otherwise. > * Bit 35 (SIZEM): Set to 1 if the fault was caused by a size mismatch between > PVALIDATE or RMPADJUST and the RMP, 0 otherwise. > * Bit 36 (VMPL): Set to 1 if the fault was caused by a VMPL permission > check failure, 0 otherwise. > * Bit 37 (SSS): Set to VMPL permission mask SSS (bit 4) value if VmplSSS is > enabled. The above bits 34-37 do not match with the bits 31,34-36 in the patch. Dongli Zhang > > Note, the APM is *extremely* misleading, and strongly implies that the > above flags can _only_ be set for #NPF exits from SNP guests. That is a > lie, as bit 34 (C-bit=1, i.e. was encrypted) can be set when running _any_ > flavor of SEV guest on SNP capable hardware. > > Signed-off-by: Sean Christopherson <seanjc@google.com> > --- > arch/x86/include/asm/kvm_host.h | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 88cc523bafa8..1e69743ef0fb 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -261,8 +261,12 @@ enum x86_intercept_stage; > #define PFERR_FETCH_MASK BIT(4) > #define PFERR_PK_MASK BIT(5) > #define PFERR_SGX_MASK BIT(15) > +#define PFERR_GUEST_RMP_MASK BIT_ULL(31) > #define PFERR_GUEST_FINAL_MASK BIT_ULL(32) > #define PFERR_GUEST_PAGE_MASK BIT_ULL(33) > +#define PFERR_GUEST_ENC_MASK BIT_ULL(34) > +#define PFERR_GUEST_SIZEM_MASK BIT_ULL(35) > +#define PFERR_GUEST_VMPL_MASK BIT_ULL(36) > #define PFERR_IMPLICIT_ACCESS BIT_ULL(48) > > #define PFERR_NESTED_GUEST_PAGE (PFERR_GUEST_PAGE_MASK | \
On Tue, Feb 27, 2024, Dongli Zhang wrote: > > > On 2/27/24 18:41, Sean Christopherson wrote: > > Define more #NPF error code flags that are relevant to SEV+ (mostly SNP) > > guests, as specified by the APM: > > > > * Bit 34 (ENC): Set to 1 if the guest’s effective C-bit was 1, 0 otherwise. > > * Bit 35 (SIZEM): Set to 1 if the fault was caused by a size mismatch between > > PVALIDATE or RMPADJUST and the RMP, 0 otherwise. > > * Bit 36 (VMPL): Set to 1 if the fault was caused by a VMPL permission > > check failure, 0 otherwise. > > * Bit 37 (SSS): Set to VMPL permission mask SSS (bit 4) value if VmplSSS is > > enabled. > > The above bits 34-37 do not match with the bits 31,34-36 in the patch. Doh, good catch. I copy+pasted this from the APM, but the RMP bit is defined slightly earlier in the APM, and I missed SSS. I'll fixup the changelog to talk about RMO, and I think I'll add SSS in v2; at the very least, having the #define will make it clear which bits are used. Thanks!
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 88cc523bafa8..1e69743ef0fb 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -261,8 +261,12 @@ enum x86_intercept_stage; #define PFERR_FETCH_MASK BIT(4) #define PFERR_PK_MASK BIT(5) #define PFERR_SGX_MASK BIT(15) +#define PFERR_GUEST_RMP_MASK BIT_ULL(31) #define PFERR_GUEST_FINAL_MASK BIT_ULL(32) #define PFERR_GUEST_PAGE_MASK BIT_ULL(33) +#define PFERR_GUEST_ENC_MASK BIT_ULL(34) +#define PFERR_GUEST_SIZEM_MASK BIT_ULL(35) +#define PFERR_GUEST_VMPL_MASK BIT_ULL(36) #define PFERR_IMPLICIT_ACCESS BIT_ULL(48) #define PFERR_NESTED_GUEST_PAGE (PFERR_GUEST_PAGE_MASK | \
Define more #NPF error code flags that are relevant to SEV+ (mostly SNP) guests, as specified by the APM: * Bit 34 (ENC): Set to 1 if the guest’s effective C-bit was 1, 0 otherwise. * Bit 35 (SIZEM): Set to 1 if the fault was caused by a size mismatch between PVALIDATE or RMPADJUST and the RMP, 0 otherwise. * Bit 36 (VMPL): Set to 1 if the fault was caused by a VMPL permission check failure, 0 otherwise. * Bit 37 (SSS): Set to VMPL permission mask SSS (bit 4) value if VmplSSS is enabled. Note, the APM is *extremely* misleading, and strongly implies that the above flags can _only_ be set for #NPF exits from SNP guests. That is a lie, as bit 34 (C-bit=1, i.e. was encrypted) can be set when running _any_ flavor of SEV guest on SNP capable hardware. Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/include/asm/kvm_host.h | 4 ++++ 1 file changed, 4 insertions(+)