The branch main has been updated by jhb:
URL:
https://cgit.FreeBSD.org/src/commit/?id=231eee17d2905682014b71d1f01719003b13bd91
commit 231eee17d2905682014b71d1f01719003b13bd91
Author: Bojan Novković <bojan.novko...@fer.hr>
AuthorDate: 2023-12-07 22:46:31 +0000
Commit: John Baldwin <j...@freebsd.org>
CommitDate: 2023-12-07 23:10:56 +0000
vmm: enable software breakpoints for AMD CPUs
This patch adds support for software breakpoint vmexits on AMD SVM.
It implements the VM_CAP_BPT_EXIT used to enable software breakpoints.
When enabled, breakpoint vmexits are passed to userspace where they
are handled by the GDB stub.
Reviewed by: jhb
Sponsored by: Google, Inc. (GSoC 2022)
Differential Revision: https://reviews.freebsd.org/D42295
---
sys/amd64/vmm/amd/svm.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/sys/amd64/vmm/amd/svm.c b/sys/amd64/vmm/amd/svm.c
index a502632f6ed6..ec0cde31aaad 100644
--- a/sys/amd64/vmm/amd/svm.c
+++ b/sys/amd64/vmm/amd/svm.c
@@ -1421,6 +1421,12 @@ svm_vmexit(struct svm_softc *svm_sc, struct svm_vcpu
*vcpu,
break;
case IDT_BP:
+ vmexit->exitcode = VM_EXITCODE_BPT;
+ vmexit->u.bpt.inst_length = vmexit->inst_length;
+ vmexit->inst_length = 0;
+
+ reflect = 0;
+ break;
case IDT_OF:
case IDT_BR:
/*
@@ -2333,6 +2339,9 @@ svm_setcap(void *vcpui, int type, int val)
if (val == 0)
error = EINVAL;
break;
+ case VM_CAP_BPT_EXIT:
+ svm_set_intercept(vcpu, VMCB_EXC_INTCPT, BIT(IDT_BP), val);
+ break;
case VM_CAP_IPI_EXIT:
vlapic = vm_lapic(vcpu->vcpu);
vlapic->ipi_exit = val;
@@ -2366,6 +2375,9 @@ svm_getcap(void *vcpui, int type, int *retval)
case VM_CAP_UNRESTRICTED_GUEST:
*retval = 1; /* unrestricted guest is always enabled */
break;
+ case VM_CAP_BPT_EXIT:
+ *retval = svm_get_intercept(vcpu, VMCB_EXC_INTCPT, BIT(IDT_BP));
+ break;
case VM_CAP_IPI_EXIT:
vlapic = vm_lapic(vcpu->vcpu);
*retval = vlapic->ipi_exit;
