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

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Message-ID: <20240507155817.3951344-4-pbonzini@redhat.com>
Date: Tue,  7 May 2024 11:58:03 -0400
From: Paolo Bonzini <pbonzini@...hat.com>
To: linux-kernel@...r.kernel.org,
	kvm@...r.kernel.org
Cc: Sean Christopherson <seanjc@...gle.com>
Subject: [PATCH 03/17] KVM: x86: Define more SEV+ page fault error bits/flags for #NPF

From: Sean Christopherson <seanjc@...gle.com>

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@...gle.com>
Message-ID: <20240228024147.41573-4-seanjc@...gle.com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.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 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