From 004804a7d77d0b63ce2f5fcb8499c94b77a5ef5c Mon Sep 17 00:00:00 2001 From: Jiri Denemark Date: Fri, 15 May 2020 22:00:29 +0200 Subject: [PATCH] qemu: Invalidate capabilities when host CPU changes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The host CPU related info stored in the capabilities cache is no longer valid after the host CPU changes. This is not a frequent situation in real world, but it can easily happen in nested scenarios when a disk image is started with various CPUs. https://bugzilla.redhat.com/show_bug.cgi?id=1778819 Signed-off-by: Jiri Denemark Reviewed-by: Ján Tomko --- src/qemu/qemu_capabilities.c | 24 ++++++++++++++++++++++++ src/qemu/qemu_capspriv.h | 1 + tests/qemucapsprobe.c | 2 +- 3 files changed, 26 insertions(+), 1 deletion(-) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index d9b339cbfb..f12769635a 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -669,6 +669,7 @@ struct _virQEMUCaps { unsigned int kvmVersion; unsigned int libvirtVersion; unsigned int microcodeVersion; + char *hostCPUSignature; char *package; char *kernelVersion; @@ -1908,6 +1909,7 @@ virQEMUCapsPtr virQEMUCapsNewCopy(virQEMUCapsPtr qemuCaps) ret->version = qemuCaps->version; ret->kvmVersion = qemuCaps->kvmVersion; ret->microcodeVersion = qemuCaps->microcodeVersion; + ret->hostCPUSignature = g_strdup(qemuCaps->hostCPUSignature); ret->package = g_strdup(qemuCaps->package); ret->kernelVersion = g_strdup(qemuCaps->kernelVersion); @@ -1964,6 +1966,7 @@ void virQEMUCapsDispose(void *obj) VIR_FREE(qemuCaps->package); VIR_FREE(qemuCaps->kernelVersion); VIR_FREE(qemuCaps->binary); + VIR_FREE(qemuCaps->hostCPUSignature); VIR_FREE(qemuCaps->gicCapabilities); @@ -4093,6 +4096,7 @@ struct _virQEMUCapsCachePriv { virArch hostArch; unsigned int microcodeVersion; char *kernelVersion; + char *hostCPUSignature; /* cache whether /dev/kvm is usable as runUid:runGuid */ virTristateBool kvmUsable; @@ -4109,6 +4113,7 @@ virQEMUCapsCachePrivFree(void *privData) VIR_FREE(priv->libDir); VIR_FREE(priv->kernelVersion); + VIR_FREE(priv->hostCPUSignature); VIR_FREE(priv); } @@ -4286,6 +4291,8 @@ virQEMUCapsLoadCache(virArch hostArch, goto cleanup; } + qemuCaps->hostCPUSignature = virXPathString("string(./hostCPUSignature)", ctxt); + if (virXPathBoolean("boolean(./package)", ctxt) > 0) { qemuCaps->package = virXPathString("string(./package)", ctxt); if (!qemuCaps->package) @@ -4587,6 +4594,8 @@ virQEMUCapsFormatCache(virQEMUCapsPtr qemuCaps) virBufferAsprintf(&buf, "%u\n", qemuCaps->microcodeVersion); + virBufferEscapeString(&buf, "%s\n", + qemuCaps->hostCPUSignature); if (qemuCaps->package) virBufferAsprintf(&buf, "%s\n", @@ -4814,6 +4823,15 @@ virQEMUCapsIsValid(void *data, } if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_KVM)) { + if (STRNEQ_NULLABLE(priv->hostCPUSignature, qemuCaps->hostCPUSignature)) { + VIR_DEBUG("Outdated capabilities for '%s': host CPU changed " + "('%s' vs '%s')", + qemuCaps->binary, + priv->hostCPUSignature, + qemuCaps->hostCPUSignature); + return false; + } + if (priv->microcodeVersion != qemuCaps->microcodeVersion) { VIR_DEBUG("Outdated capabilities for '%s': microcode version " "changed (%u vs %u)", @@ -5286,6 +5304,7 @@ virQEMUCapsNewForBinaryInternal(virArch hostArch, const char *libDir, uid_t runUid, gid_t runGid, + const char *hostCPUSignature, unsigned int microcodeVersion, const char *kernelVersion) { @@ -5324,6 +5343,7 @@ virQEMUCapsNewForBinaryInternal(virArch hostArch, virQEMUCapsInitHostCPUModel(qemuCaps, hostArch, VIR_DOMAIN_VIRT_QEMU); if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_KVM)) { + qemuCaps->hostCPUSignature = g_strdup(hostCPUSignature); qemuCaps->microcodeVersion = microcodeVersion; qemuCaps->kernelVersion = g_strdup(kernelVersion); @@ -5349,6 +5369,7 @@ virQEMUCapsNewData(const char *binary, priv->libDir, priv->runUid, priv->runGid, + priv->hostCPUSignature, virHostCPUGetMicrocodeVersion(), priv->kernelVersion); } @@ -5448,6 +5469,9 @@ virQEMUCapsCacheNew(const char *libDir, priv->hostArch = virArchFromHost(); + if (virHostCPUGetSignature(&priv->hostCPUSignature) < 0) + goto error; + priv->runUid = runUid; priv->runGid = runGid; priv->kvmUsable = VIR_TRISTATE_BOOL_ABSENT; diff --git a/src/qemu/qemu_capspriv.h b/src/qemu/qemu_capspriv.h index 4c053af195..5d2f448e41 100644 --- a/src/qemu/qemu_capspriv.h +++ b/src/qemu/qemu_capspriv.h @@ -33,6 +33,7 @@ virQEMUCapsNewForBinaryInternal(virArch hostArch, const char *libDir, uid_t runUid, gid_t runGid, + const char *hostCPUSignature, unsigned int microcodeVersion, const char *kernelVersion); diff --git a/tests/qemucapsprobe.c b/tests/qemucapsprobe.c index ea88fd2e8a..26ea9ff5ed 100644 --- a/tests/qemucapsprobe.c +++ b/tests/qemucapsprobe.c @@ -77,7 +77,7 @@ main(int argc, char **argv) return EXIT_FAILURE; if (!(caps = virQEMUCapsNewForBinaryInternal(VIR_ARCH_NONE, argv[1], "/tmp", - -1, -1, 0, NULL))) + -1, -1, NULL, 0, NULL))) return EXIT_FAILURE; virObjectUnref(caps); -- GitLab