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Diffstat (limited to 'arch/x86/kvm/svm/nested.c')
-rw-r--r--arch/x86/kvm/svm/nested.c39
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;
}