[PATCH 05/12] KVM: x86: pass the whole hflags field to emulator and back

[Paolo Bonzini]

The hflags field will contain information about system management mode
and will be useful for the emulator.  Pass the entire field rather than
just the guest-mode information.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
	RFC->v1: introduce kvm_set_hflags
---
 arch/x86/include/asm/kvm_emulate.h |  5 ++++-
 arch/x86/kvm/emulate.c             |  6 +++---
 arch/x86/kvm/x86.c                 | 10 +++++++++-
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index 57a9d94fe160..7410879a41f7 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -262,6 +262,9 @@ enum x86emul_mode {
 	X86EMUL_MODE_PROT64,	/* 64-bit (long) mode.    */
 };
 
+/* These match some of the HF_* flags defined in kvm_host.h  */
+#define X86EMUL_GUEST_MASK           (1 << 5) /* VCPU is in guest-mode */
+
 struct x86_emulate_ctxt {
 	const struct x86_emulate_ops *ops;
 
@@ -273,8 +276,8 @@ struct x86_emulate_ctxt {
 
 	/* interruptibility state, as a result of execution of STI or MOV SS */
 	int interruptibility;
+	int emul_flags;
 
-	bool guest_mode; /* guest running a nested guest */
 	bool perm_ok; /* do not check permissions if true */
 	bool ud;	/* inject an #UD if host doesn't support insn */
 
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 5839fc56cb3e..e82a559df21a 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -4871,7 +4871,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
 				fetch_possible_mmx_operand(ctxt, &ctxt->dst);
 		}
 
-		if (unlikely(ctxt->guest_mode) && (ctxt->d & Intercept)) {
+		if (unlikely(ctxt->emul_flags & X86EMUL_GUEST_MASK) && ctxt->intercept) {
 			rc = emulator_check_intercept(ctxt, ctxt->intercept,
 						      X86_ICPT_PRE_EXCEPT);
 			if (rc != X86EMUL_CONTINUE)
@@ -4900,7 +4900,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
 				goto done;
 		}
 
-		if (unlikely(ctxt->guest_mode) && (ctxt->d & Intercept)) {
+		if (unlikely(ctxt->emul_flags & X86EMUL_GUEST_MASK) && (ctxt->d & Intercept)) {
 			rc = emulator_check_intercept(ctxt, ctxt->intercept,
 						      X86_ICPT_POST_EXCEPT);
 			if (rc != X86EMUL_CONTINUE)
@@ -4953,7 +4953,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
 
 special_insn:
 
-	if (unlikely(ctxt->guest_mode) && (ctxt->d & Intercept)) {
+	if (unlikely(ctxt->emul_flags & X86EMUL_GUEST_MASK) && (ctxt->d & Intercept)) {
 		rc = emulator_check_intercept(ctxt, ctxt->intercept,
 					      X86_ICPT_POST_MEMACCESS);
 		if (rc != X86EMUL_CONTINUE)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 52df3ac6a6bc..7d311a0de84c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5176,7 +5176,8 @@ static void init_emulate_ctxt(struct kvm_vcpu *vcpu)
 		     (cs_l && is_long_mode(vcpu))	? X86EMUL_MODE_PROT64 :
 		     cs_db				? X86EMUL_MODE_PROT32 :
 							  X86EMUL_MODE_PROT16;
-	ctxt->guest_mode = is_guest_mode(vcpu);
+	BUILD_BUG_ON(HF_GUEST_MASK != X86EMUL_GUEST_MASK);
+	ctxt->emul_flags = vcpu->arch.hflags;
 
 	init_decode_cache(ctxt);
 	vcpu->arch.emulate_regs_need_sync_from_vcpu = false;
@@ -5345,6 +5346,11 @@ static bool retry_instruction(struct x86_emulate_ctxt *ctxt,
 static int complete_emulated_mmio(struct kvm_vcpu *vcpu);
 static int complete_emulated_pio(struct kvm_vcpu *vcpu);
 
+void kvm_set_hflags(struct kvm_vcpu *vcpu, unsigned emul_flags)
+{
+	vcpu->arch.hflags = emul_flags;
+}
+
 static int kvm_vcpu_check_hw_bp(unsigned long addr, u32 type, u32 dr7,
 				unsigned long *db)
 {
@@ -5544,6 +5550,8 @@ restart:
 		unsigned long rflags = kvm_x86_ops->get_rflags(vcpu);
 		toggle_interruptibility(vcpu, ctxt->interruptibility);
 		vcpu->arch.emulate_regs_need_sync_to_vcpu = false;
+		if (vcpu->arch.hflags != ctxt->emul_flags)
+			kvm_set_hflags(vcpu, ctxt->emul_flags);
 		kvm_rip_write(vcpu, ctxt->eip);
 		if (r == EMULATE_DONE)
 			kvm_vcpu_check_singlestep(vcpu, rflags, &r);
-- 
1.8.3.1


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