From 6ab0b9feb82a7ac09956e6761fec73cd47789df5 Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Tue, 14 Nov 2017 16:54:24 -0500 Subject: [PATCH] x86,kvm: remove KVM emulator get_fpu / put_fpu Now that get_fpu and put_fpu do nothing, because the scheduler will automatically load and restore the guest FPU context for us while we are in this code (deep inside the vcpu_run main loop), we can get rid of the get_fpu and put_fpu hooks. Signed-off-by: Rik van Riel Suggested-by: David Hildenbrand Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_emulate.h | 2 -- arch/x86/kvm/emulate.c | 24 ------------------------ arch/x86/kvm/x86.c | 10 ---------- 3 files changed, 36 deletions(-) diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 034caa1a084e..b24b1c8b3979 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -214,8 +214,6 @@ struct x86_emulate_ops { void (*halt)(struct x86_emulate_ctxt *ctxt); void (*wbinvd)(struct x86_emulate_ctxt *ctxt); int (*fix_hypercall)(struct x86_emulate_ctxt *ctxt); - void (*get_fpu)(struct x86_emulate_ctxt *ctxt); /* disables preempt */ - void (*put_fpu)(struct x86_emulate_ctxt *ctxt); /* reenables preempt */ int (*intercept)(struct x86_emulate_ctxt *ctxt, struct x86_instruction_info *info, enum x86_intercept_stage stage); diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index e7d04d0c8008..abe74f779f9d 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1046,7 +1046,6 @@ static void fetch_register_operand(struct operand *op) static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg) { - ctxt->ops->get_fpu(ctxt); switch (reg) { case 0: asm("movdqa %%xmm0, %0" : "=m"(*data)); break; case 1: asm("movdqa %%xmm1, %0" : "=m"(*data)); break; @@ -1068,13 +1067,11 @@ static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg) #endif default: BUG(); } - ctxt->ops->put_fpu(ctxt); } static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg) { - ctxt->ops->get_fpu(ctxt); switch (reg) { case 0: asm("movdqa %0, %%xmm0" : : "m"(*data)); break; case 1: asm("movdqa %0, %%xmm1" : : "m"(*data)); break; @@ -1096,12 +1093,10 @@ static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, #endif default: BUG(); } - ctxt->ops->put_fpu(ctxt); } static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg) { - ctxt->ops->get_fpu(ctxt); switch (reg) { case 0: asm("movq %%mm0, %0" : "=m"(*data)); break; case 1: asm("movq %%mm1, %0" : "=m"(*data)); break; @@ -1113,12 +1108,10 @@ static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg) case 7: asm("movq %%mm7, %0" : "=m"(*data)); break; default: BUG(); } - ctxt->ops->put_fpu(ctxt); } static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg) { - ctxt->ops->get_fpu(ctxt); switch (reg) { case 0: asm("movq %0, %%mm0" : : "m"(*data)); break; case 1: asm("movq %0, %%mm1" : : "m"(*data)); break; @@ -1130,7 +1123,6 @@ static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg) case 7: asm("movq %0, %%mm7" : : "m"(*data)); break; default: BUG(); } - ctxt->ops->put_fpu(ctxt); } static int em_fninit(struct x86_emulate_ctxt *ctxt) @@ -1138,9 +1130,7 @@ static int em_fninit(struct x86_emulate_ctxt *ctxt) if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) return emulate_nm(ctxt); - ctxt->ops->get_fpu(ctxt); asm volatile("fninit"); - ctxt->ops->put_fpu(ctxt); return X86EMUL_CONTINUE; } @@ -1151,9 +1141,7 @@ static int em_fnstcw(struct x86_emulate_ctxt *ctxt) if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) return emulate_nm(ctxt); - ctxt->ops->get_fpu(ctxt); asm volatile("fnstcw %0": "+m"(fcw)); - ctxt->ops->put_fpu(ctxt); ctxt->dst.val = fcw; @@ -1167,9 +1155,7 @@ static int em_fnstsw(struct x86_emulate_ctxt *ctxt) if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) return emulate_nm(ctxt); - ctxt->ops->get_fpu(ctxt); asm volatile("fnstsw %0": "+m"(fsw)); - ctxt->ops->put_fpu(ctxt); ctxt->dst.val = fsw; @@ -4001,12 +3987,8 @@ static int em_fxsave(struct x86_emulate_ctxt *ctxt) if (rc != X86EMUL_CONTINUE) return rc; - ctxt->ops->get_fpu(ctxt); - rc = asm_safe("fxsave %[fx]", , [fx] "+m"(fx_state)); - ctxt->ops->put_fpu(ctxt); - if (rc != X86EMUL_CONTINUE) return rc; @@ -4049,8 +4031,6 @@ static int em_fxrstor(struct x86_emulate_ctxt *ctxt) if (rc != X86EMUL_CONTINUE) return rc; - ctxt->ops->get_fpu(ctxt); - if (size < __fxstate_size(16)) { rc = fxregs_fixup(&fx_state, size); if (rc != X86EMUL_CONTINUE) @@ -4066,8 +4046,6 @@ static int em_fxrstor(struct x86_emulate_ctxt *ctxt) rc = asm_safe("fxrstor %[fx]", : [fx] "m"(fx_state)); out: - ctxt->ops->put_fpu(ctxt); - return rc; } @@ -5317,9 +5295,7 @@ static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt) { int rc; - ctxt->ops->get_fpu(ctxt); rc = asm_safe("fwait"); - ctxt->ops->put_fpu(ctxt); if (unlikely(rc != X86EMUL_CONTINUE)) return emulate_exception(ctxt, MF_VECTOR, 0, false); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c8da1680a7d6..6ca747abfa2f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5251,14 +5251,6 @@ static void emulator_halt(struct x86_emulate_ctxt *ctxt) emul_to_vcpu(ctxt)->arch.halt_request = 1; } -static void emulator_get_fpu(struct x86_emulate_ctxt *ctxt) -{ -} - -static void emulator_put_fpu(struct x86_emulate_ctxt *ctxt) -{ -} - static int emulator_intercept(struct x86_emulate_ctxt *ctxt, struct x86_instruction_info *info, enum x86_intercept_stage stage) @@ -5336,8 +5328,6 @@ static const struct x86_emulate_ops emulate_ops = { .halt = emulator_halt, .wbinvd = emulator_wbinvd, .fix_hypercall = emulator_fix_hypercall, - .get_fpu = emulator_get_fpu, - .put_fpu = emulator_put_fpu, .intercept = emulator_intercept, .get_cpuid = emulator_get_cpuid, .set_nmi_mask = emulator_set_nmi_mask,