From b742c1e6e79ddf4192d76336da2407c65ca7242f Mon Sep 17 00:00:00 2001 From: Ladi Prosek Date: Thu, 22 Jun 2017 09:05:26 +0200 Subject: KVM: SVM: handle singlestep exception when skipping emulated instructions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit kvm_skip_emulated_instruction handles the singlestep debug exception which is something we almost always want. This commit (specifically the change in rdmsr_interception) makes the debug.flat KVM unit test pass on AMD. Two call sites still call skip_emulated_instruction directly: * In svm_queue_exception where it's used only for moving the rip forward * In task_switch_interception which is analogous to handle_task_switch in VMX Signed-off-by: Ladi Prosek Signed-off-by: Radim Krčmář --- arch/x86/kvm/svm.c | 59 ++++++++++++++++++++++++++++++------------------------ 1 file changed, 33 insertions(+), 26 deletions(-) (limited to 'arch') diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 905ea6052517..3da42d7c629e 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -2267,7 +2267,7 @@ static int io_interception(struct vcpu_svm *svm) { struct kvm_vcpu *vcpu = &svm->vcpu; u32 io_info = svm->vmcb->control.exit_info_1; /* address size bug? */ - int size, in, string; + int size, in, string, ret; unsigned port; ++svm->vcpu.stat.io_exits; @@ -2279,10 +2279,16 @@ static int io_interception(struct vcpu_svm *svm) port = io_info >> 16; size = (io_info & SVM_IOIO_SIZE_MASK) >> SVM_IOIO_SIZE_SHIFT; svm->next_rip = svm->vmcb->control.exit_info_2; - skip_emulated_instruction(&svm->vcpu); + ret = kvm_skip_emulated_instruction(&svm->vcpu); - return in ? kvm_fast_pio_in(vcpu, size, port) - : kvm_fast_pio_out(vcpu, size, port); + /* + * TODO: we might be squashing a KVM_GUESTDBG_SINGLESTEP-triggered + * KVM_EXIT_DEBUG here. + */ + if (in) + return kvm_fast_pio_in(vcpu, size, port) && ret; + else + return kvm_fast_pio_out(vcpu, size, port) && ret; } static int nmi_interception(struct vcpu_svm *svm) @@ -3055,6 +3061,7 @@ static int vmload_interception(struct vcpu_svm *svm) { struct vmcb *nested_vmcb; struct page *page; + int ret; if (nested_svm_check_permissions(svm)) return 1; @@ -3064,18 +3071,19 @@ static int vmload_interception(struct vcpu_svm *svm) return 1; svm->next_rip = kvm_rip_read(&svm->vcpu) + 3; - skip_emulated_instruction(&svm->vcpu); + ret = kvm_skip_emulated_instruction(&svm->vcpu); nested_svm_vmloadsave(nested_vmcb, svm->vmcb); nested_svm_unmap(page); - return 1; + return ret; } static int vmsave_interception(struct vcpu_svm *svm) { struct vmcb *nested_vmcb; struct page *page; + int ret; if (nested_svm_check_permissions(svm)) return 1; @@ -3085,12 +3093,12 @@ static int vmsave_interception(struct vcpu_svm *svm) return 1; svm->next_rip = kvm_rip_read(&svm->vcpu) + 3; - skip_emulated_instruction(&svm->vcpu); + ret = kvm_skip_emulated_instruction(&svm->vcpu); nested_svm_vmloadsave(svm->vmcb, nested_vmcb); nested_svm_unmap(page); - return 1; + return ret; } static int vmrun_interception(struct vcpu_svm *svm) @@ -3123,25 +3131,29 @@ failed: static int stgi_interception(struct vcpu_svm *svm) { + int ret; + if (nested_svm_check_permissions(svm)) return 1; svm->next_rip = kvm_rip_read(&svm->vcpu) + 3; - skip_emulated_instruction(&svm->vcpu); + ret = kvm_skip_emulated_instruction(&svm->vcpu); kvm_make_request(KVM_REQ_EVENT, &svm->vcpu); enable_gif(svm); - return 1; + return ret; } static int clgi_interception(struct vcpu_svm *svm) { + int ret; + if (nested_svm_check_permissions(svm)) return 1; svm->next_rip = kvm_rip_read(&svm->vcpu) + 3; - skip_emulated_instruction(&svm->vcpu); + ret = kvm_skip_emulated_instruction(&svm->vcpu); disable_gif(svm); @@ -3152,7 +3164,7 @@ static int clgi_interception(struct vcpu_svm *svm) mark_dirty(svm->vmcb, VMCB_INTR); } - return 1; + return ret; } static int invlpga_interception(struct vcpu_svm *svm) @@ -3166,8 +3178,7 @@ static int invlpga_interception(struct vcpu_svm *svm) kvm_mmu_invlpg(vcpu, kvm_register_read(&svm->vcpu, VCPU_REGS_RAX)); svm->next_rip = kvm_rip_read(&svm->vcpu) + 3; - skip_emulated_instruction(&svm->vcpu); - return 1; + return kvm_skip_emulated_instruction(&svm->vcpu); } static int skinit_interception(struct vcpu_svm *svm) @@ -3190,7 +3201,7 @@ static int xsetbv_interception(struct vcpu_svm *svm) if (kvm_set_xcr(&svm->vcpu, index, new_bv) == 0) { svm->next_rip = kvm_rip_read(&svm->vcpu) + 3; - skip_emulated_instruction(&svm->vcpu); + return kvm_skip_emulated_instruction(&svm->vcpu); } return 1; @@ -3286,8 +3297,7 @@ static int invlpg_interception(struct vcpu_svm *svm) return emulate_instruction(&svm->vcpu, 0) == EMULATE_DONE; kvm_mmu_invlpg(&svm->vcpu, svm->vmcb->control.exit_info_1); - skip_emulated_instruction(&svm->vcpu); - return 1; + return kvm_skip_emulated_instruction(&svm->vcpu); } static int emulate_on_interception(struct vcpu_svm *svm) @@ -3437,9 +3447,7 @@ static int dr_interception(struct vcpu_svm *svm) kvm_register_write(&svm->vcpu, reg, val); } - skip_emulated_instruction(&svm->vcpu); - - return 1; + return kvm_skip_emulated_instruction(&svm->vcpu); } static int cr8_write_interception(struct vcpu_svm *svm) @@ -3562,6 +3570,7 @@ static int rdmsr_interception(struct vcpu_svm *svm) if (svm_get_msr(&svm->vcpu, &msr_info)) { trace_kvm_msr_read_ex(ecx); kvm_inject_gp(&svm->vcpu, 0); + return 1; } else { trace_kvm_msr_read(ecx, msr_info.data); @@ -3570,9 +3579,8 @@ static int rdmsr_interception(struct vcpu_svm *svm) kvm_register_write(&svm->vcpu, VCPU_REGS_RDX, msr_info.data >> 32); svm->next_rip = kvm_rip_read(&svm->vcpu) + 2; - skip_emulated_instruction(&svm->vcpu); + return kvm_skip_emulated_instruction(&svm->vcpu); } - return 1; } static int svm_set_vm_cr(struct kvm_vcpu *vcpu, u64 data) @@ -3698,11 +3706,11 @@ static int wrmsr_interception(struct vcpu_svm *svm) if (kvm_set_msr(&svm->vcpu, &msr)) { trace_kvm_msr_write_ex(ecx, data); kvm_inject_gp(&svm->vcpu, 0); + return 1; } else { trace_kvm_msr_write(ecx, data); - skip_emulated_instruction(&svm->vcpu); + return kvm_skip_emulated_instruction(&svm->vcpu); } - return 1; } static int msr_interception(struct vcpu_svm *svm) @@ -3731,8 +3739,7 @@ static int pause_interception(struct vcpu_svm *svm) static int nop_interception(struct vcpu_svm *svm) { - skip_emulated_instruction(&(svm->vcpu)); - return 1; + return kvm_skip_emulated_instruction(&(svm->vcpu)); } static int monitor_interception(struct vcpu_svm *svm) -- cgit v1.2.3-59-g8ed1b