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| author | Jan Kiszka <jan.kiszka@siemens.com> | 2012-09-21 05:42:55 +0200 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2012-09-23 15:00:07 +0200 |
| commit | c863901075a42d50678616d8ee4b96ef13080498 (patch) | |
| tree | 947ffa1bd109f15b9cb483c8257fb028d0ed7df3 /arch/x86/kvm/x86.c | |
| parent | 7a84428af7ca6a847f058c9ff244a18a2664fd1b (diff) | |
| download | lwn-c863901075a42d50678616d8ee4b96ef13080498.tar.gz lwn-c863901075a42d50678616d8ee4b96ef13080498.zip | |
KVM: x86: Fix guest debug across vcpu INIT reset
If we reset a vcpu on INIT, we so far overwrote dr7 as provided by
KVM_SET_GUEST_DEBUG, and we also cleared switch_db_regs unconditionally.
Fix this by saving the dr7 used for guest debugging and calculating the
effective register value as well as switch_db_regs on any potential
change. This will change to focus of the set_guest_debug vendor op to
update_dp_bp_intercept.
Found while trying to stop on start_secondary.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 7d44204c6041..b16d4a5bfa41 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -692,6 +692,18 @@ unsigned long kvm_get_cr8(struct kvm_vcpu *vcpu) } EXPORT_SYMBOL_GPL(kvm_get_cr8); +static void kvm_update_dr7(struct kvm_vcpu *vcpu) +{ + unsigned long dr7; + + if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) + dr7 = vcpu->arch.guest_debug_dr7; + else + dr7 = vcpu->arch.dr7; + kvm_x86_ops->set_dr7(vcpu, dr7); + vcpu->arch.switch_db_regs = (dr7 & DR7_BP_EN_MASK); +} + static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val) { switch (dr) { @@ -717,10 +729,7 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val) if (val & 0xffffffff00000000ULL) return -1; /* #GP */ vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1; - if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) { - kvm_x86_ops->set_dr7(vcpu, vcpu->arch.dr7); - vcpu->arch.switch_db_regs = (val & DR7_BP_EN_MASK); - } + kvm_update_dr7(vcpu); break; } @@ -5851,13 +5860,12 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) { for (i = 0; i < KVM_NR_DB_REGS; ++i) vcpu->arch.eff_db[i] = dbg->arch.debugreg[i]; - vcpu->arch.switch_db_regs = - (dbg->arch.debugreg[7] & DR7_BP_EN_MASK); + vcpu->arch.guest_debug_dr7 = dbg->arch.debugreg[7]; } else { for (i = 0; i < KVM_NR_DB_REGS; i++) vcpu->arch.eff_db[i] = vcpu->arch.db[i]; - vcpu->arch.switch_db_regs = (vcpu->arch.dr7 & DR7_BP_EN_MASK); } + kvm_update_dr7(vcpu); if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) vcpu->arch.singlestep_rip = kvm_rip_read(vcpu) + @@ -5869,7 +5877,7 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, */ kvm_set_rflags(vcpu, rflags); - kvm_x86_ops->set_guest_debug(vcpu, dbg); + kvm_x86_ops->update_db_bp_intercept(vcpu); r = 0; @@ -6045,10 +6053,10 @@ int kvm_arch_vcpu_reset(struct kvm_vcpu *vcpu) vcpu->arch.nmi_pending = 0; vcpu->arch.nmi_injected = false; - vcpu->arch.switch_db_regs = 0; memset(vcpu->arch.db, 0, sizeof(vcpu->arch.db)); vcpu->arch.dr6 = DR6_FIXED_1; vcpu->arch.dr7 = DR7_FIXED_1; + kvm_update_dr7(vcpu); kvm_make_request(KVM_REQ_EVENT, vcpu); vcpu->arch.apf.msr_val = 0; |