Merge branch 'kvm-amd-fixes' into HEAD

[linux-block.git] / arch / x86 / kvm / svm / nested.c

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index a7c3b3030e590d1c58bd2ccfd47711018774f3e5..1429f506fe9eca16cc2ab24175a4a5f43bb947c2 100644 (file)
--- 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"
@@ -271,7 +272,7 @@ 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;
@@ -490,7 +491,7 @@ 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;
@@ -614,26 +615,45 @@ 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)
@@ -690,6 +710,9 @@ 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;
                }