diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2026-05-01 00:02:12 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2026-05-10 14:52:29 +0200 |
| commit | 949aa12e030eac4424f4832eb93e96c20719ae7b (patch) | |
| tree | 676fc9ad0aa528a4ce08295de7daebbaa1380de4 | |
| parent | 296b29597db1cf96b955da0f1bcb34d2759dd9d7 (diff) | |
KVM: x86/mmu: separate more EPT/non-EPT permission_fault()
Move more of EPT handling entirely in the existing "if (!ept)"
conditional. Use a new "rf" variable instead of uf for read permissions
for clarity.
Merge smepf and ff into a single variable because EPT's "SMEP" (actually
MBEC) is defined differently and does not need smepf.
Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 26 |
1 files changed, 15 insertions, 11 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index d94a488db79d..891b0cc5d38c 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -5584,24 +5584,28 @@ static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) * that causes a fault with the given PFEC. */ + /* Faults from reads to non-readable pages */ + u8 rf = 0; /* Faults from writes to non-writable pages */ u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; /* Faults from user mode accesses to supervisor pages */ - u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; - /* Faults from fetches of non-executable pages*/ - u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; - /* Faults from kernel mode fetches of user pages */ - u8 smepf = 0; + u8 uf = 0; + /* Faults from fetches of non-executable pages */ + u8 ff = 0; /* Faults from kernel mode accesses of user pages */ u8 smapf = 0; - if (!ept) { + if (ept) { + rf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; + ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; + } else { /* Faults from kernel mode accesses to user pages */ u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; - /* Not really needed: !nx will cause pte.nx to fault */ - if (!efer_nx) - ff = 0; + uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; + + if (efer_nx) + ff |= (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; /* Allow supervisor writes if !cr0.wp */ if (!cr0_wp) @@ -5609,7 +5613,7 @@ static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) /* Disallow supervisor fetches of user code if cr4.smep */ if (cr4_smep) - smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; + ff |= (pfec & PFERR_FETCH_MASK) ? kf : 0; /* * SMAP:kernel-mode data accesses from user-mode @@ -5630,7 +5634,7 @@ static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; } - mmu->permissions[index] = ff | uf | wf | smepf | smapf; + mmu->permissions[index] = ff | uf | wf | rf | smapf; } } |