From 32e69f232db4ca11f26e5961daeff93906ce232f Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Tue, 29 Nov 2022 21:37:11 +0200 Subject: [PATCH] KVM: x86: Use emulator callbacks instead of duplicating "host flags" Instead of re-defining the "host flags" bits, just expose dedicated helpers for each of the two remaining flags that are consumed by the emulator. The emulator never consumes both "is guest" and "is SMM" in close proximity, so there is no motivation to avoid additional indirect branches. Also while at it, garbage collect the recently removed host flags. No functional change is intended. Signed-off-by: Maxim Levitsky Tested-by: Santosh Shukla Link: https://lore.kernel.org/r/20221129193717.513824-6-mlevitsk@redhat.com [sean: fix CONFIG_KVM_SMM=n builds, tweak names of wrappers] Signed-off-by: Sean Christopherson --- arch/x86/include/asm/kvm_host.h | 6 +++--- arch/x86/kvm/emulate.c | 11 +++++------ arch/x86/kvm/kvm_emulate.h | 7 ++----- arch/x86/kvm/smm.c | 2 -- arch/x86/kvm/x86.c | 14 +++++++++----- 5 files changed, 19 insertions(+), 21 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index e653b0b7ff77..3b0436b1f93c 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -2074,11 +2074,11 @@ enum { TASK_SWITCH_GATE = 3, }; -#define HF_GUEST_MASK (1 << 5) /* VCPU is in guest-mode */ +#define HF_GUEST_MASK (1 << 0) /* VCPU is in guest-mode */ #ifdef CONFIG_KVM_SMM -#define HF_SMM_MASK (1 << 6) -#define HF_SMM_INSIDE_NMI_MASK (1 << 7) +#define HF_SMM_MASK (1 << 1) +#define HF_SMM_INSIDE_NMI_MASK (1 << 2) # define __KVM_VCPU_MULTIPLE_ADDRESS_SPACE # define KVM_ADDRESS_SPACE_NUM 2 diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index c3443045cd93..5f7d9082c835 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2310,7 +2310,7 @@ static int em_lseg(struct x86_emulate_ctxt *ctxt) static int em_rsm(struct x86_emulate_ctxt *ctxt) { - if ((ctxt->ops->get_hflags(ctxt) & X86EMUL_SMM_MASK) == 0) + if (!ctxt->ops->is_smm(ctxt)) return emulate_ud(ctxt); if (ctxt->ops->leave_smm(ctxt)) @@ -5133,7 +5133,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) const struct x86_emulate_ops *ops = ctxt->ops; int rc = X86EMUL_CONTINUE; int saved_dst_type = ctxt->dst.type; - unsigned emul_flags; + bool is_guest_mode = ctxt->ops->is_guest_mode(ctxt); ctxt->mem_read.pos = 0; @@ -5148,7 +5148,6 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) goto done; } - emul_flags = ctxt->ops->get_hflags(ctxt); if (unlikely(ctxt->d & (No64|Undefined|Sse|Mmx|Intercept|CheckPerm|Priv|Prot|String))) { if ((ctxt->mode == X86EMUL_MODE_PROT64 && (ctxt->d & No64)) || @@ -5182,7 +5181,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) fetch_possible_mmx_operand(&ctxt->dst); } - if (unlikely(emul_flags & X86EMUL_GUEST_MASK) && ctxt->intercept) { + if (unlikely(is_guest_mode) && ctxt->intercept) { rc = emulator_check_intercept(ctxt, ctxt->intercept, X86_ICPT_PRE_EXCEPT); if (rc != X86EMUL_CONTINUE) @@ -5211,7 +5210,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) goto done; } - if (unlikely(emul_flags & X86EMUL_GUEST_MASK) && (ctxt->d & Intercept)) { + if (unlikely(is_guest_mode) && (ctxt->d & Intercept)) { rc = emulator_check_intercept(ctxt, ctxt->intercept, X86_ICPT_POST_EXCEPT); if (rc != X86EMUL_CONTINUE) @@ -5265,7 +5264,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) special_insn: - if (unlikely(emul_flags & X86EMUL_GUEST_MASK) && (ctxt->d & Intercept)) { + if (unlikely(is_guest_mode) && (ctxt->d & Intercept)) { rc = emulator_check_intercept(ctxt, ctxt->intercept, X86_ICPT_POST_MEMACCESS); if (rc != X86EMUL_CONTINUE) diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h index 2d9662be8333..ab65f3a47dfd 100644 --- a/arch/x86/kvm/kvm_emulate.h +++ b/arch/x86/kvm/kvm_emulate.h @@ -220,7 +220,8 @@ struct x86_emulate_ops { void (*set_nmi_mask)(struct x86_emulate_ctxt *ctxt, bool masked); - unsigned (*get_hflags)(struct x86_emulate_ctxt *ctxt); + bool (*is_smm)(struct x86_emulate_ctxt *ctxt); + bool (*is_guest_mode)(struct x86_emulate_ctxt *ctxt); int (*leave_smm)(struct x86_emulate_ctxt *ctxt); void (*triple_fault)(struct x86_emulate_ctxt *ctxt); int (*set_xcr)(struct x86_emulate_ctxt *ctxt, u32 index, u64 xcr); @@ -275,10 +276,6 @@ 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 */ -#define X86EMUL_SMM_MASK (1 << 6) - /* * fastop functions are declared as taking a never-defined fastop parameter, * so they can't be called from C directly. diff --git a/arch/x86/kvm/smm.c b/arch/x86/kvm/smm.c index cc43638d48a3..b42111a24cc2 100644 --- a/arch/x86/kvm/smm.c +++ b/arch/x86/kvm/smm.c @@ -111,8 +111,6 @@ static void check_smram_offsets(void) void kvm_smm_changed(struct kvm_vcpu *vcpu, bool entering_smm) { - BUILD_BUG_ON(HF_SMM_MASK != X86EMUL_SMM_MASK); - trace_kvm_smm_transition(vcpu->vcpu_id, vcpu->arch.smbase, entering_smm); if (entering_smm) { diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 508074e47bc0..cf9e3d213c83 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8150,9 +8150,14 @@ static void emulator_set_nmi_mask(struct x86_emulate_ctxt *ctxt, bool masked) static_call(kvm_x86_set_nmi_mask)(emul_to_vcpu(ctxt), masked); } -static unsigned emulator_get_hflags(struct x86_emulate_ctxt *ctxt) +static bool emulator_is_smm(struct x86_emulate_ctxt *ctxt) { - return emul_to_vcpu(ctxt)->arch.hflags; + return is_smm(emul_to_vcpu(ctxt)); +} + +static bool emulator_is_guest_mode(struct x86_emulate_ctxt *ctxt) +{ + return is_guest_mode(emul_to_vcpu(ctxt)); } #ifndef CONFIG_KVM_SMM @@ -8221,7 +8226,8 @@ static const struct x86_emulate_ops emulate_ops = { .guest_has_fxsr = emulator_guest_has_fxsr, .guest_has_rdpid = emulator_guest_has_rdpid, .set_nmi_mask = emulator_set_nmi_mask, - .get_hflags = emulator_get_hflags, + .is_smm = emulator_is_smm, + .is_guest_mode = emulator_is_guest_mode, .leave_smm = emulator_leave_smm, .triple_fault = emulator_triple_fault, .set_xcr = emulator_set_xcr, @@ -8293,8 +8299,6 @@ 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; - BUILD_BUG_ON(HF_GUEST_MASK != X86EMUL_GUEST_MASK); - ctxt->interruptibility = 0; ctxt->have_exception = false; ctxt->exception.vector = -1;