Re: [PATCH v12 05/29] KVM: x86: Define RMP page fault error bits for #NPF

Paolo Bonzini
2024-03-30T19:29:04Z

On 3/29/24 23:58, Michael Roth wrote:
> From: Brijesh Singh <brijesh.singh@amd.com>
>
> When SEV-SNP is enabled globally, the hardware places restrictions on
> all memory accesses based on the RMP entry, whether the hypervisor or a
> VM, performs the accesses. When hardware encounters an RMP access
> violation during a guest access, it will cause a #VMEXIT(NPF) with a
> number of additional bits set to indicate the reasons for the #NPF.
> Define those here.
>
> See APM2 section 16.36.10 for more details.
>
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
> [mdr: add some additional details to commit message]
> Signed-off-by: Michael Roth <michael.roth@amd.com>

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

One nit below.

> ---
> arch/x86/include/asm/kvm_host.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 90dc0ae9311a..a3f8eba8d8b6 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -262,9 +262,12 @@ enum x86_intercept_stage;
> #define PFERR_FETCH_BIT 4
> #define PFERR_PK_BIT 5
> #define PFERR_SGX_BIT 15
> +#define PFERR_GUEST_RMP_BIT 31
> #define PFERR_GUEST_FINAL_BIT 32
> #define PFERR_GUEST_PAGE_BIT 33
> #define PFERR_GUEST_ENC_BIT 34
> +#define PFERR_GUEST_SIZEM_BIT 35
> +#define PFERR_GUEST_VMPL_BIT 36
> #define PFERR_IMPLICIT_ACCESS_BIT 48
>
> #define PFERR_PRESENT_MASK BIT(PFERR_PRESENT_BIT)
> @@ -277,7 +280,10 @@ enum x86_intercept_stage;
> #define PFERR_GUEST_FINAL_MASK BIT_ULL(PFERR_GUEST_FINAL_BIT)
> #define PFERR_GUEST_PAGE_MASK BIT_ULL(PFERR_GUEST_PAGE_BIT)
> #define PFERR_GUEST_ENC_MASK BIT_ULL(PFERR_GUEST_ENC_BIT)
> +#define PFERR_GUEST_RMP_MASK BIT_ULL(PFERR_GUEST_RMP_BIT)
> +#define PFERR_GUEST_SIZEM_MASK BIT_ULL(PFERR_GUEST_SIZEM_BIT)
> #define PFERR_IMPLICIT_ACCESS BIT_ULL(PFERR_IMPLICIT_ACCESS_BIT)
> +#define PFERR_GUEST_VMPL_MASK BIT_ULL(PFERR_GUEST_VMPL_BIT)

Should be kept in either bit order or perhaps alphabetical order
(probably bit is better).

Paolo

> #define PFERR_NESTED_GUEST_PAGE (PFERR_GUEST_PAGE_MASK | \
> PFERR_WRITE_MASK | \