diff options
| author | Nadav Amit <namit@cs.technion.ac.il> | 2015-04-19 21:12:59 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-05-19 20:52:35 +0200 |
| commit | 3db176d5b4170284d9ce1e1e9c441ebfa9a37417 (patch) | |
| tree | 6fb6a64518cb5a652ee538c8c2c231a5bc540c1a /arch/x86/kvm/emulate.c | |
| parent | cba3d2765e9fcbce45fa3930c4d5f4da7652e752 (diff) | |
KVM: x86: Fix DR7 mask on task-switch while debugging
If the host sets hardware breakpoints to debug the guest, and a task-switch
occurs in the guest, the architectural DR7 will not be updated. The effective
DR7 would be updated instead.
This fix puts the DR7 update during task-switch emulation, so it now uses the
standard DR setting mechanism instead of the one that was previously used. As a
bonus, the update of DR7 will now be effective for AMD as well.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/emulate.c')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 5839fc56cb3e..b32a38e6e287 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -25,6 +25,7 @@ #include <linux/module.h> #include <asm/kvm_emulate.h> #include <linux/stringify.h> +#include <asm/debugreg.h> #include "x86.h" #include "tss.h" @@ -2849,7 +2850,7 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, ulong old_tss_base = ops->get_cached_segment_base(ctxt, VCPU_SREG_TR); u32 desc_limit; - ulong desc_addr; + ulong desc_addr, dr7; /* FIXME: old_tss_base == ~0 ? */ @@ -2934,6 +2935,9 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, ret = em_push(ctxt); } + ops->get_dr(ctxt, 7, &dr7); + ops->set_dr(ctxt, 7, dr7 & ~(DR_LOCAL_ENABLE_MASK | DR_LOCAL_SLOWDOWN)); + return ret; } |