diff options
Diffstat (limited to 'arch/x86/kvm/svm/nested.c')
| -rw-r--r-- | arch/x86/kvm/svm/nested.c | 39 |
1 files changed, 31 insertions, 8 deletions
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 90a1ca939627..9a2a62e5afeb 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -19,6 +19,7 @@ #include <linux/kernel.h> #include <asm/msr-index.h> +#include <asm/debugreg.h> #include "kvm_emulate.h" #include "trace.h" @@ -267,7 +268,7 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa, svm->vmcb->save.rsp = nested_vmcb->save.rsp; svm->vmcb->save.rip = nested_vmcb->save.rip; svm->vmcb->save.dr7 = nested_vmcb->save.dr7; - svm->vmcb->save.dr6 = nested_vmcb->save.dr6; + svm->vcpu.arch.dr6 = nested_vmcb->save.dr6; svm->vmcb->save.cpl = nested_vmcb->save.cpl; svm->nested.vmcb_msrpm = nested_vmcb->control.msrpm_base_pa & ~0x0fffULL; @@ -482,7 +483,7 @@ int nested_svm_vmexit(struct vcpu_svm *svm) nested_vmcb->save.rsp = vmcb->save.rsp; nested_vmcb->save.rax = vmcb->save.rax; nested_vmcb->save.dr7 = vmcb->save.dr7; - nested_vmcb->save.dr6 = vmcb->save.dr6; + nested_vmcb->save.dr6 = svm->vcpu.arch.dr6; nested_vmcb->save.cpl = vmcb->save.cpl; nested_vmcb->control.int_ctl = vmcb->control.int_ctl; @@ -606,26 +607,45 @@ static int nested_svm_exit_handled_msr(struct vcpu_svm *svm) /* DB exceptions for our internal use must not cause vmexit */ static int nested_svm_intercept_db(struct vcpu_svm *svm) { - unsigned long dr6; + unsigned long dr6 = svm->vmcb->save.dr6; + + /* Always catch it and pass it to userspace if debugging. */ + if (svm->vcpu.guest_debug & + (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) + return NESTED_EXIT_HOST; /* if we're not singlestepping, it's not ours */ if (!svm->nmi_singlestep) - return NESTED_EXIT_DONE; + goto reflected_db; /* if it's not a singlestep exception, it's not ours */ - if (kvm_get_dr(&svm->vcpu, 6, &dr6)) - return NESTED_EXIT_DONE; if (!(dr6 & DR6_BS)) - return NESTED_EXIT_DONE; + goto reflected_db; /* if the guest is singlestepping, it should get the vmexit */ if (svm->nmi_singlestep_guest_rflags & X86_EFLAGS_TF) { disable_nmi_singlestep(svm); - return NESTED_EXIT_DONE; + goto reflected_db; } /* it's ours, the nested hypervisor must not see this one */ return NESTED_EXIT_HOST; + +reflected_db: + /* + * Synchronize guest DR6 here just like in kvm_deliver_exception_payload; + * it will be moved into the nested VMCB by nested_svm_vmexit. Once + * exceptions will be moved to svm_check_nested_events, all this stuff + * will just go away and we could just return NESTED_EXIT_HOST + * unconditionally. db_interception will queue the exception, which + * will be processed by svm_check_nested_events if a nested vmexit is + * required, and we will just use kvm_deliver_exception_payload to copy + * the payload to DR6 before vmexit. + */ + WARN_ON(svm->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT); + svm->vcpu.arch.dr6 &= ~(DR_TRAP_BITS | DR6_RTM); + svm->vcpu.arch.dr6 |= dr6 & ~DR6_FIXED_1; + return NESTED_EXIT_DONE; } static int nested_svm_intercept_ioio(struct vcpu_svm *svm) @@ -682,6 +702,9 @@ static int nested_svm_intercept(struct vcpu_svm *svm) if (svm->nested.intercept_exceptions & excp_bits) { if (exit_code == SVM_EXIT_EXCP_BASE + DB_VECTOR) vmexit = nested_svm_intercept_db(svm); + else if (exit_code == SVM_EXIT_EXCP_BASE + BP_VECTOR && + svm->vcpu.guest_debug & KVM_GUESTDBG_USE_SW_BP) + vmexit = NESTED_EXIT_HOST; else vmexit = NESTED_EXIT_DONE; } |