[libvirt] [PATCH 3/3] qemu: caps: Advertise arm 32-on-64 KVM option
We need to use qemu-system-aarch64 to run armv7l KVM VMs on an aarch64
host.
---
src/qemu/qemu_capabilities.c | 42 ++++++++++++++++++++++--------------------
1 file changed, 22 insertions(+), 20 deletions(-)
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 1e7bddb..7181865 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -723,19 +723,6 @@ virQEMUCapsFindBinaryForArch(virArch hostarch,
return ret;
}
-
-static bool
-virQEMUCapsIsValidForKVM(virArch hostarch,
- virArch guestarch)
-{
- if (hostarch == guestarch)
- return true;
- if (hostarch == VIR_ARCH_X86_64 &&
- guestarch == VIR_ARCH_I686)
- return true;
- return false;
-}
-
static int
virQEMUCapsInitGuest(virCapsPtr caps,
virQEMUCapsCachePtr cache,
@@ -747,6 +734,7 @@ virQEMUCapsInitGuest(virCapsPtr caps,
char *binary = NULL;
virQEMUCapsPtr qemubinCaps = NULL;
virQEMUCapsPtr kvmbinCaps = NULL;
+ bool native_kvm, x86_32on64_kvm, arm_32on64_kvm;
int ret = -1;
/* Check for existence of base emulator, or alternate base
@@ -764,16 +752,30 @@ virQEMUCapsInitGuest(virCapsPtr caps,
/* qemu-kvm/kvm binaries can only be used if
* - host & guest arches match
- * Or
- * - hostarch is x86_64 and guest arch is i686
- * The latter simply needs "-cpu qemu32"
+ * - hostarch is x86_64 and guest arch is i686 (needs -cpu qemu32)
+ * - hostarch is aarch64 and guest arch is armv7l (needs -cpu aarch64=off)
*/
- if (virQEMUCapsIsValidForKVM(hostarch, guestarch)) {
- const char *const kvmbins[] = { "/usr/libexec/qemu-kvm", /* RHEL */
- "qemu-kvm", /* Fedora */
- "kvm" }; /* Upstream .spec */
+ native_kvm = (hostarch == guestarch);
+ x86_32on64_kvm = (hostarch == VIR_ARCH_X86_64 &&
+ guestarch == VIR_ARCH_I686);
+ arm_32on64_kvm = (hostarch == VIR_ARCH_AARCH64 &&
+ guestarch == VIR_ARCH_ARMV7L);
+
+ if (native_kvm || x86_32on64_kvm || arm_32on64_kvm) {
+ const char *kvmbins[] = {
+ "/usr/libexec/qemu-kvm", /* RHEL */
+ "qemu-kvm", /* Fedora */
+ "kvm", /* Debian/Ubuntu */
+ NULL,
+ };
+
+ if (arm_32on64_kvm)
+ kvmbins[3] = "qemu-system-aarch64";
for (i = 0; i < ARRAY_CARDINALITY(kvmbins); ++i) {
+ if (!kvmbins[i])
+ continue;
+
kvmbin = virFindFileInPath(kvmbins[i]);
if (!kvmbin)
--
2.4.1