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>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 30bcb95..5d46c90 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2288,16 +2288,6 @@
}
}
-static void set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)
-{
- if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
- vmcs_writel(GUEST_DR7, dbg->arch.debugreg[7]);
- else
- vmcs_writel(GUEST_DR7, vcpu->arch.dr7);
-
- update_exception_bitmap(vcpu);
-}
-
static __init int cpu_has_kvm_support(void)
{
return cpu_has_vmx();
@@ -3960,8 +3950,6 @@
kvm_rip_write(vcpu, 0);
kvm_register_write(vcpu, VCPU_REGS_RSP, 0);
- vmcs_writel(GUEST_DR7, 0x400);
-
vmcs_writel(GUEST_GDTR_BASE, 0);
vmcs_write32(GUEST_GDTR_LIMIT, 0xffff);
@@ -7237,7 +7225,7 @@
.vcpu_load = vmx_vcpu_load,
.vcpu_put = vmx_vcpu_put,
- .set_guest_debug = set_guest_debug,
+ .update_db_bp_intercept = update_exception_bitmap,
.get_msr = vmx_get_msr,
.set_msr = vmx_set_msr,
.get_segment_base = vmx_get_segment_base,