D61218.1793951817.diff
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	diff --git a/sys/amd64/vmm/amd/svm.c b/sys/amd64/vmm/amd/svm.c
	--- a/sys/amd64/vmm/amd/svm.c
	+++ b/sys/amd64/vmm/amd/svm.c
	@@ -2079,7 +2079,8 @@
	* VMCB.
	*/
	load_dr7(0);
	- wrmsr(MSR_DEBUGCTLMSR, 0);
	+ if (gctx->host_debugctl != 0)
	+ wrmsr(MSR_DEBUGCTLMSR, 0);

	/* Save host debug registers. */
	gctx->host_dr0 = rdr0();
	@@ -2114,7 +2115,12 @@
	load_dr2(gctx->host_dr2);
	load_dr3(gctx->host_dr3);
	load_dr6(gctx->host_dr6);
	- wrmsr(MSR_DEBUGCTLMSR, gctx->host_debugctl);
	+ /*
	+ * LBR virtualization restores the zero DEBUGCTL value used at VMRUN.
	+ * Only a nonzero original host value needs restoring here.
	+ */
	+ if (gctx->host_debugctl != 0)
	+ wrmsr(MSR_DEBUGCTLMSR, gctx->host_debugctl);
	load_dr7(gctx->host_dr7);
	}