[PATCH 6.12.y 2/5] KVM: x86: Route non-canonical checks in emulator through emulate_ops

[Sasha Levin <sashal@kernel.org>]

From: Maxim Levitsky <mlevitsk@redhat.com>

[ Upstream commit 16ccadefa295af434ca296e566f078223ecd79ca ]

Add emulate_ops.is_canonical_addr() to perform (non-)canonical checks in
the emulator, which will allow extending is_noncanonical_address() to
support different flavors of canonical checks, e.g. for descriptor table
bases vs. MSRs, without needing duplicate logic in the emulator.

No functional change is intended.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20240906221824.491834-3-mlevitsk@redhat.com
[sean: separate from additional of flags, massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Stable-dep-of: fa787ac07b3c ("KVM: x86/hyper-v: Skip non-canonical addresses during PV TLB flush")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/x86/kvm/emulate.c     | 2 +-
 arch/x86/kvm/kvm_emulate.h | 2 ++
 arch/x86/kvm/x86.c         | 7 +++++++
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index e72aed25d7212..3ce83f57d267d 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -653,7 +653,7 @@ static inline u8 ctxt_virt_addr_bits(struct x86_emulate_ctxt *ctxt)
 static inline bool emul_is_noncanonical_address(u64 la,
 						struct x86_emulate_ctxt *ctxt)
 {
-	return !__is_canonical_address(la, ctxt_virt_addr_bits(ctxt));
+	return !ctxt->ops->is_canonical_addr(ctxt, la);
 }
 
 /*
diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
index 55a18e2f2dcd9..1b1843ff210fd 100644
--- a/arch/x86/kvm/kvm_emulate.h
+++ b/arch/x86/kvm/kvm_emulate.h
@@ -235,6 +235,8 @@ struct x86_emulate_ops {
 
 	gva_t (*get_untagged_addr)(struct x86_emulate_ctxt *ctxt, gva_t addr,
 				   unsigned int flags);
+
+	bool (*is_canonical_addr)(struct x86_emulate_ctxt *ctxt, gva_t addr);
 };
 
 /* Type, address-of, and value of an instruction's operand. */
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f378d479fea3f..d7416dc7f4974 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8608,6 +8608,12 @@ static gva_t emulator_get_untagged_addr(struct x86_emulate_ctxt *ctxt,
 					       addr, flags);
 }
 
+static bool emulator_is_canonical_addr(struct x86_emulate_ctxt *ctxt,
+				       gva_t addr)
+{
+	return !is_noncanonical_address(addr, emul_to_vcpu(ctxt));
+}
+
 static const struct x86_emulate_ops emulate_ops = {
 	.vm_bugged           = emulator_vm_bugged,
 	.read_gpr            = emulator_read_gpr,
@@ -8654,6 +8660,7 @@ static const struct x86_emulate_ops emulate_ops = {
 	.triple_fault        = emulator_triple_fault,
 	.set_xcr             = emulator_set_xcr,
 	.get_untagged_addr   = emulator_get_untagged_addr,
+	.is_canonical_addr   = emulator_is_canonical_addr,
 };
 
 static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask)
-- 
2.39.5