[PATCH 03/17] KVM: x86: Define more SEV+ page fault error bits/flags for #NPF

From: Paolo Bonzini
Date: Tue May 07 2024 - 11:59:47 EST


From: Sean Christopherson <seanjc@xxxxxxxxxx>

Define more #NPF error code flags that are relevant to SEV+ (mostly SNP)
guests, as specified by the APM:

* Bit 31 (RMP): Set to 1 if the fault was caused due to an RMP check or a
VMPL check failure, 0 otherwise.
* 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.

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@xxxxxxxxxx>
Message-ID: <20240228024147.41573-4-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
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 a047480da5af..58bbcf76ad1e 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 | \
--
2.43.0