[libvirt] [PATCH 5/6] qemu: add support for Direct Mode for Hyper-V Synthetic timers

Vitaly Kuznetsov vkuznets at redhat.com
Thu Jul 25 13:52:17 UTC 2019


QEMU-4.1 supports 'Direct Mode' for Hyper-V synthetic timers
(hv-stimer-direct CPU flag): Windows guests can request that timer
expiration notifications are delivered as normal interrupts (and not
VMBus messages). This is used by Hyper-V on KVM.

Signed-off-by: Vitaly Kuznetsov <vkuznets at redhat.com>
---
 src/qemu/qemu_command.c             | 22 ++++++++++++++--
 src/qemu/qemu_process.c             | 39 +++++++++++++++++++++++++++--
 tests/qemuxml2argvdata/hyperv.args  |  4 +--
 tests/qemuxml2argvdata/hyperv.xml   |  4 ++-
 tests/qemuxml2xmloutdata/hyperv.xml |  4 ++-
 5 files changed, 65 insertions(+), 8 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 1cf165079f..12229e879e 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -7096,7 +7096,7 @@ qemuBuildCpuCommandLine(virCommandPtr cmd,
     int ret = -1;
     virBuffer cpu_buf = VIR_BUFFER_INITIALIZER;
     virBuffer buf = VIR_BUFFER_INITIALIZER;
-    size_t i;
+    size_t i, j;
 
     if (def->cpu &&
         (def->cpu->mode != VIR_CPU_MODE_CUSTOM || def->cpu->model)) {
@@ -7158,7 +7158,6 @@ qemuBuildCpuCommandLine(virCommandPtr cmd,
             case VIR_DOMAIN_HYPERV_VPINDEX:
             case VIR_DOMAIN_HYPERV_RUNTIME:
             case VIR_DOMAIN_HYPERV_SYNIC:
-            case VIR_DOMAIN_HYPERV_STIMER:
             case VIR_DOMAIN_HYPERV_RESET:
             case VIR_DOMAIN_HYPERV_FREQUENCIES:
             case VIR_DOMAIN_HYPERV_REENLIGHTENMENT:
@@ -7170,6 +7169,25 @@ qemuBuildCpuCommandLine(virCommandPtr cmd,
                                       virDomainHypervTypeToString(i));
                 break;
 
+            case VIR_DOMAIN_HYPERV_STIMER:
+                if (def->hyperv_features[i] == VIR_TRISTATE_SWITCH_ON)
+                    virBufferAsprintf(&buf, ",hv_%s",
+                                      virDomainHypervTypeToString(i));
+                for (j = 0; j < VIR_DOMAIN_HYPERV_STIMER_LAST; j++) {
+                    switch ((virDomainHypervStimer) j) {
+                    case VIR_DOMAIN_HYPERV_STIMER_DIRECT:
+                        if (def->hyperv_stimer_features[j] == VIR_TRISTATE_SWITCH_ON)
+                            virBufferAsprintf(&buf, ",hv_stimer_%s",
+                                              virDomainHypervStimerTypeToString(j));
+                        break;
+
+                        /* coverity[dead_error_begin] */
+                    case VIR_DOMAIN_HYPERV_STIMER_LAST:
+                        break;
+                    }
+                }
+                break;
+
             case VIR_DOMAIN_HYPERV_SPINLOCKS:
                 if (def->hyperv_features[i] == VIR_TRISTATE_SWITCH_ON)
                     virBufferAsprintf(&buf, ",hv_spinlocks=0x%x",
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 75205bc121..0235cfd022 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -4111,10 +4111,45 @@ qemuProcessVerifyHypervFeatures(virDomainDefPtr def,
         rc = virCPUDataCheckFeature(cpu, cpuFeature);
         VIR_FREE(cpuFeature);
 
-        if (rc < 0)
+        if (rc < 0) {
             return -1;
-        else if (rc == 1)
+        } else if (rc == 1) {
+            if ((i == VIR_DOMAIN_HYPERV_STIMER)) {
+                size_t j;
+
+                for (j = 0; j < VIR_DOMAIN_HYPERV_STIMER_LAST; j++) {
+                    switch ((virDomainHypervStimer) j) {
+                    case VIR_DOMAIN_HYPERV_STIMER_DIRECT:
+                        if (def->hyperv_stimer_features[j] != VIR_TRISTATE_SWITCH_ON)
+                            continue;
+
+                        if (virAsprintf(&cpuFeature, "__kvm_hv_stimer_%s",
+                                        virDomainHypervStimerTypeToString(j)) < 0)
+                            return -1;
+
+                        rc = virCPUDataCheckFeature(cpu, cpuFeature);
+                        VIR_FREE(cpuFeature);
+
+                        if (rc < 0)
+                            return -1;
+                        else if (rc == 1)
+                            continue;
+
+                        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                                       _("host doesn't support hyperv stimer '%s' feature"),
+                                       virDomainHypervStimerTypeToString(i));
+                        return -1;
+
+                        /* coverity[dead_error_begin] */
+                    case VIR_DOMAIN_HYPERV_STIMER_LAST:
+                        break;
+                    }
+                }
+
+            }
+
             continue;
+        }
 
         switch ((virDomainHyperv) i) {
         case VIR_DOMAIN_HYPERV_RELAXED:
diff --git a/tests/qemuxml2argvdata/hyperv.args b/tests/qemuxml2argvdata/hyperv.args
index c557b6d8fe..a8f47ebb21 100644
--- a/tests/qemuxml2argvdata/hyperv.args
+++ b/tests/qemuxml2argvdata/hyperv.args
@@ -12,8 +12,8 @@ QEMU_AUDIO_DRV=none \
 -S \
 -machine pc,accel=tcg,usb=off,dump-guest-core=off \
 -cpu 'qemu32,hv_relaxed,hv_vapic,hv_spinlocks=0x2fff,hv_vpindex,hv_runtime,\
-hv_synic,hv_stimer,hv_reset,hv_vendor_id=KVM Hv,hv_frequencies,\
-hv_reenlightenment,hv_tlbflush,hv_ipi,hv_evmcs' \
+hv_synic,hv_stimer,hv_stimer_direct,hv_reset,hv_vendor_id=KVM Hv,\
+hv_frequencies,hv_reenlightenment,hv_tlbflush,hv_ipi,hv_evmcs' \
 -m 214 \
 -realtime mlock=off \
 -smp 6,sockets=6,cores=1,threads=1 \
diff --git a/tests/qemuxml2argvdata/hyperv.xml b/tests/qemuxml2argvdata/hyperv.xml
index c6feaed528..ae0f934f76 100644
--- a/tests/qemuxml2argvdata/hyperv.xml
+++ b/tests/qemuxml2argvdata/hyperv.xml
@@ -17,7 +17,9 @@
       <vpindex state='on'/>
       <runtime state='on'/>
       <synic state='on'/>
-      <stimer state='on'/>
+      <stimer state='on'>
+        <direct state='on'/>
+      </stimer>
       <reset state='on'/>
       <vendor_id state='on' value='KVM Hv'/>
       <frequencies state='on'/>
diff --git a/tests/qemuxml2xmloutdata/hyperv.xml b/tests/qemuxml2xmloutdata/hyperv.xml
index 5510d3dfad..2e4b43d4c6 100644
--- a/tests/qemuxml2xmloutdata/hyperv.xml
+++ b/tests/qemuxml2xmloutdata/hyperv.xml
@@ -17,7 +17,9 @@
       <vpindex state='on'/>
       <runtime state='on'/>
       <synic state='on'/>
-      <stimer state='on'/>
+      <stimer state='on'>
+        <direct state='on'/>
+      </stimer>
       <reset state='on'/>
       <vendor_id state='on' value='KVM Hv'/>
       <frequencies state='on'/>
-- 
2.20.1




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