git: 181afaaaee00 - main - vmm: implement VM_CAP_MASK_HWINTR on AMD CPUs

[John Baldwin]

The branch main has been updated by jhb:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=181afaaaee0025f948346fe8b9ec5356a0cdef97

commit 181afaaaee0025f948346fe8b9ec5356a0cdef97
Author:     Bojan Novković <bojan.novko...@fer.hr>
AuthorDate: 2023-12-07 23:08:58 +0000
Commit:     John Baldwin <j...@freebsd.org>
CommitDate: 2023-12-07 23:11:04 +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
---
 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;