git: b879ddc755b7 - stable/14 - vmm: implement VM_CAP_MASK_HWINTR on AMD CPUs

The branch stable/14 has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=b879ddc755b7eb36e1cd2468f9b55ddb3088c850

commit b879ddc755b7eb36e1cd2468f9b55ddb3088c850
Author:     Bojan Novković <bojan.novkovic@fer.hr>
AuthorDate: 2023-12-07 23:08:58 +0000
Commit:     John Baldwin <jhb@FreeBSD.org>
CommitDate: 2024-01-05 00:25:49 +0000

    vmm: implement VM_CAP_MASK_HWINTR on AMD CPUs
    
    This patch implements the interrupt blocking VM capability on AMD
    CPUs.  Implementing this capability allows the GDB stub to single-step
    a virtual machine without landing inside interrupt handlers.
    
    Reviewed by:    jhb, corvink
    Sponsored by:   Google, Inc. (GSoC 2022)
    Differential Revision:  https://reviews.freebsd.org/D42299
    
    (cherry picked from commit 181afaaaee0025f948346fe8b9ec5356a0cdef97)
---
 sys/amd64/vmm/amd/svm.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/sys/amd64/vmm/amd/svm.c b/sys/amd64/vmm/amd/svm.c
index 1507377a0cfe..3fda9454090b 100644
--- a/sys/amd64/vmm/amd/svm.c
+++ b/sys/amd64/vmm/amd/svm.c
@@ -1725,6 +1725,10 @@ svm_inj_interrupts(struct svm_softc *sc, struct svm_vcpu *vcpu,
 	int vector, need_intr_window;
 	int extint_pending;
 
+	if (vcpu->caps & (1 << VM_CAP_MASK_HWINTR)) {
+		return;
+	}
+
 	state = svm_get_vmcb_state(vcpu);
 	ctrl  = svm_get_vmcb_ctrl(vcpu);
 
@@ -2446,6 +2450,10 @@ svm_setcap(void *vcpui, int type, int val)
 		vlapic = vm_lapic(vcpu->vcpu);
 		vlapic->ipi_exit = val;
 		break;
+	case VM_CAP_MASK_HWINTR:
+		vcpu->caps &= ~(1 << VM_CAP_MASK_HWINTR);
+		vcpu->caps |= (val << VM_CAP_MASK_HWINTR);
+		break;
 	case VM_CAP_RFLAGS_TF: {
 		uint64_t rflags;
 
@@ -2529,6 +2537,9 @@ svm_getcap(void *vcpui, int type, int *retval)
 	case VM_CAP_RFLAGS_TF:
 		*retval = !!(vcpu->caps & (1 << VM_CAP_RFLAGS_TF));
 		break;
+	case VM_CAP_MASK_HWINTR:
+		*retval = !!(vcpu->caps & (1 << VM_CAP_MASK_HWINTR));
+		break;
 	default:
 		error = ENOENT;
 		break;