From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Sean Christopherson <seanjc@google.com>
Subject: [PATCH 02/17] KVM: x86: Remove separate "bit" defines for page fault error code masks
Date: Tue, 7 May 2024 11:58:02 -0400 [thread overview]
Message-ID: <20240507155817.3951344-3-pbonzini@redhat.com> (raw)
In-Reply-To: <20240507155817.3951344-1-pbonzini@redhat.com>
From: Sean Christopherson <seanjc@google.com>
Open code the bit number directly in the PFERR_* masks and drop the
intermediate PFERR_*_BIT defines, as having to bounce through two macros
just to see which flag corresponds to which bit is quite annoying, as is
having to define two macros just to add recognition of a new flag.
Use ternary operator to derive the bit in permission_fault(), the one
function that actually needs the bit number as part of clever shifting
to avoid conditional branches. Generally the compiler is able to turn
it into a conditional move, and if not it's not really a big deal.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240228024147.41573-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/include/asm/kvm_host.h | 32 ++++++++++----------------------
arch/x86/kvm/mmu.h | 5 ++---
2 files changed, 12 insertions(+), 25 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 9f92bdb78504..a047480da5af 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -254,28 +254,16 @@ enum x86_intercept_stage;
KVM_GUESTDBG_INJECT_DB | \
KVM_GUESTDBG_BLOCKIRQ)
-
-#define PFERR_PRESENT_BIT 0
-#define PFERR_WRITE_BIT 1
-#define PFERR_USER_BIT 2
-#define PFERR_RSVD_BIT 3
-#define PFERR_FETCH_BIT 4
-#define PFERR_PK_BIT 5
-#define PFERR_SGX_BIT 15
-#define PFERR_GUEST_FINAL_BIT 32
-#define PFERR_GUEST_PAGE_BIT 33
-#define PFERR_IMPLICIT_ACCESS_BIT 48
-
-#define PFERR_PRESENT_MASK BIT(PFERR_PRESENT_BIT)
-#define PFERR_WRITE_MASK BIT(PFERR_WRITE_BIT)
-#define PFERR_USER_MASK BIT(PFERR_USER_BIT)
-#define PFERR_RSVD_MASK BIT(PFERR_RSVD_BIT)
-#define PFERR_FETCH_MASK BIT(PFERR_FETCH_BIT)
-#define PFERR_PK_MASK BIT(PFERR_PK_BIT)
-#define PFERR_SGX_MASK BIT(PFERR_SGX_BIT)
-#define PFERR_GUEST_FINAL_MASK BIT_ULL(PFERR_GUEST_FINAL_BIT)
-#define PFERR_GUEST_PAGE_MASK BIT_ULL(PFERR_GUEST_PAGE_BIT)
-#define PFERR_IMPLICIT_ACCESS BIT_ULL(PFERR_IMPLICIT_ACCESS_BIT)
+#define PFERR_PRESENT_MASK BIT(0)
+#define PFERR_WRITE_MASK BIT(1)
+#define PFERR_USER_MASK BIT(2)
+#define PFERR_RSVD_MASK BIT(3)
+#define PFERR_FETCH_MASK BIT(4)
+#define PFERR_PK_MASK BIT(5)
+#define PFERR_SGX_MASK BIT(15)
+#define PFERR_GUEST_FINAL_MASK BIT_ULL(32)
+#define PFERR_GUEST_PAGE_MASK BIT_ULL(33)
+#define PFERR_IMPLICIT_ACCESS BIT_ULL(48)
#define PFERR_NESTED_GUEST_PAGE (PFERR_GUEST_PAGE_MASK | \
PFERR_WRITE_MASK | \
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 60f21bb4c27b..2343c9f00e31 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -213,7 +213,7 @@ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
*/
u64 implicit_access = access & PFERR_IMPLICIT_ACCESS;
bool not_smap = ((rflags & X86_EFLAGS_AC) | implicit_access) == X86_EFLAGS_AC;
- int index = (pfec + (not_smap << PFERR_RSVD_BIT)) >> 1;
+ int index = (pfec | (not_smap ? PFERR_RSVD_MASK : 0)) >> 1;
u32 errcode = PFERR_PRESENT_MASK;
bool fault;
@@ -234,8 +234,7 @@ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
pkru_bits = (vcpu->arch.pkru >> (pte_pkey * 2)) & 3;
/* clear present bit, replace PFEC.RSVD with ACC_USER_MASK. */
- offset = (pfec & ~1) +
- ((pte_access & PT_USER_MASK) << (PFERR_RSVD_BIT - PT_USER_SHIFT));
+ offset = (pfec & ~1) | ((pte_access & PT_USER_MASK) ? PFERR_RSVD_MASK : 0);
pkru_bits &= mmu->pkru_mask >> offset;
errcode |= -pkru_bits & PFERR_PK_MASK;
--
2.43.0
next prev parent reply other threads:[~2024-05-07 15:58 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-07 15:58 [PATCH v2 00/17] KVM: x86/mmu: Page fault and MMIO cleanups Paolo Bonzini
2024-05-07 15:58 ` [PATCH 01/17] KVM: x86/mmu: Exit to userspace with -EFAULT if private fault hits emulation Paolo Bonzini
2024-05-13 5:25 ` Xiaoyao Li
2024-05-07 15:58 ` Paolo Bonzini [this message]
2024-05-13 5:29 ` [PATCH 02/17] KVM: x86: Remove separate "bit" defines for page fault error code masks Xiaoyao Li
2024-05-07 15:58 ` [PATCH 03/17] KVM: x86: Define more SEV+ page fault error bits/flags for #NPF Paolo Bonzini
2024-05-07 15:58 ` [PATCH 04/17] KVM: x86: Move synthetic PFERR_* sanity checks to SVM's #NPF handler Paolo Bonzini
2024-05-13 5:50 ` Xiaoyao Li
2024-05-13 17:31 ` Sean Christopherson
2024-05-14 4:25 ` Xiaoyao Li
2024-05-14 15:32 ` Sean Christopherson
2024-05-15 1:03 ` Xiaoyao Li
2024-05-07 15:58 ` [PATCH 05/17] KVM: x86/mmu: Pass full 64-bit error code when handling page faults Paolo Bonzini
2024-05-07 15:58 ` [PATCH 06/17] KVM: x86/mmu: WARN if upper 32 bits of legacy #PF error code are non-zero Paolo Bonzini
2024-05-07 15:58 ` [PATCH 07/17] KVM: x86/mmu: Use synthetic page fault error code to indicate private faults Paolo Bonzini
2024-05-13 5:56 ` Xiaoyao Li
2024-05-07 15:58 ` [PATCH 08/17] KVM: x86/mmu: check for invalid async page faults involving private memory Paolo Bonzini
2024-05-07 15:58 ` [PATCH 09/17] KVM: x86/mmu: WARN and skip MMIO cache on private, reserved page faults Paolo Bonzini
2024-05-13 6:15 ` Xiaoyao Li
2024-05-07 15:58 ` [PATCH 10/17] KVM: x86/mmu: Move private vs. shared check above slot validity checks Paolo Bonzini
2024-05-13 6:22 ` Xiaoyao Li
2024-05-07 15:58 ` [PATCH 11/17] KVM: x86/mmu: Don't force emulation of L2 accesses to non-APIC internal slots Paolo Bonzini
2024-05-07 15:58 ` [PATCH 12/17] KVM: x86/mmu: Explicitly disallow private accesses to emulated MMIO Paolo Bonzini
2024-05-13 6:26 ` Xiaoyao Li
2024-05-07 15:58 ` [PATCH 13/17] KVM: x86/mmu: Move slot checks from __kvm_faultin_pfn() to kvm_faultin_pfn() Paolo Bonzini
2024-05-13 6:27 ` Xiaoyao Li
2024-05-07 15:58 ` [PATCH 14/17] KVM: x86/mmu: Handle no-slot faults at the beginning of kvm_faultin_pfn() Paolo Bonzini
2024-05-13 6:28 ` Xiaoyao Li
2024-05-07 15:58 ` [PATCH 15/17] KVM: x86/mmu: Set kvm_page_fault.hva to KVM_HVA_ERR_BAD for "no slot" faults Paolo Bonzini
2024-05-13 6:28 ` Xiaoyao Li
2024-05-07 15:58 ` [PATCH 16/17] KVM: x86/mmu: Initialize kvm_page_fault's pfn and hva to error values Paolo Bonzini
2024-05-13 6:29 ` Xiaoyao Li
2024-05-07 15:58 ` [PATCH 17/17] KVM: x86/mmu: Sanity check that __kvm_faultin_pfn() doesn't create noslot pfns Paolo Bonzini
2024-05-13 6:40 ` Xiaoyao Li
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