| Message ID | d4d77b18bee5121a8e172069fa331fb72836f27e.1571155220.git.crobinso@redhat.com |
|---|---|
| State | Accepted |
| Commit | fbf7c23c2dfae0ff879c98130c3765b4c1ebf34e |
| Headers | show |
| Series | qemu: caps: Use unique key for domCaps caching | expand |
On 10/15/19 1:01 PM, Cole Robinson wrote: > When searching qemuCaps->domCapsCache for existing domCaps data, > we check for a matching pair of arch+virttype+machine+emulator. However > for the hash table key we only use the machine string. So if the > cache already contains: > > x86_64 + kvm + pc + /usr/bin/qemu-kvm > > But a new VM is defined with > > x86_64 + qemu + pc + /usr/bin/qemu-kvm > > We correctly fail to find matching cached domCaps, but then attempt > to use a colliding key with virHashAddEntry > > Fix this by building a hash key from the 4 values, not just machine > > Signed-off-by: Cole Robinson <crobinso@redhat.com> > --- > qemu_domain.c validation should be affected, but it is covered up > by another bug, fixed here: > https://www.redhat.com/archives/libvir-list/2019-October/msg00708.html > > src/qemu/qemu_conf.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c > index 08cd784054..64ac8cbdd3 100644 > --- a/src/qemu/qemu_conf.c > +++ b/src/qemu/qemu_conf.c > @@ -1396,6 +1396,8 @@ virQEMUDriverGetDomainCapabilities(virQEMUDriverPtr driver, > domCaps = virHashSearch(domCapsCache, > virQEMUDriverSearchDomcaps, &data, NULL); > if (!domCaps) { > + VIR_AUTOFREE(char *) key = NULL; > + "g_autofree char *key = NULL;" instead of VIR_AUTOFREE for extra karma points. Everything else LGTM. Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com> > /* hash miss, build new domcaps */ > if (!(domCaps = virDomainCapsNew(data.path, data.machine, > data.arch, data.virttype))) > @@ -1406,7 +1408,14 @@ virQEMUDriverGetDomainCapabilities(virQEMUDriverPtr driver, > cfg->firmwares, cfg->nfirmwares) < 0) > return NULL; > > - if (virHashAddEntry(domCapsCache, machine, domCaps) < 0) > + if (virAsprintf(&key, "%d:%d:%s:%s", > + data.arch, > + data.virttype, > + NULLSTR(data.machine), > + NULLSTR(data.path)) < 0) > + return NULL; > + > + if (virHashAddEntry(domCapsCache, key, domCaps) < 0) > return NULL; > } > -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
On Wed, 2019-10-16 at 09:12 -0300, Daniel Henrique Barboza wrote: > > On 10/15/19 1:01 PM, Cole Robinson wrote: > > When searching qemuCaps->domCapsCache for existing domCaps data, > > we check for a matching pair of arch+virttype+machine+emulator. > > However > > for the hash table key we only use the machine string. So if the > > cache already contains: > > > > x86_64 + kvm + pc + /usr/bin/qemu-kvm > > > > But a new VM is defined with > > > > x86_64 + qemu + pc + /usr/bin/qemu-kvm > > > > We correctly fail to find matching cached domCaps, but then attempt > > to use a colliding key with virHashAddEntry > > > > Fix this by building a hash key from the 4 values, not just machine > > > > Signed-off-by: Cole Robinson <crobinso@redhat.com> > > --- > > qemu_domain.c validation should be affected, but it is covered up > > by another bug, fixed here: > > https://www.redhat.com/archives/libvir-list/2019-October/msg00708.html > > > > src/qemu/qemu_conf.c | 11 ++++++++++- > > 1 file changed, 10 insertions(+), 1 deletion(-) > > > > diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c > > index 08cd784054..64ac8cbdd3 100644 > > --- a/src/qemu/qemu_conf.c > > +++ b/src/qemu/qemu_conf.c > > @@ -1396,6 +1396,8 @@ > > virQEMUDriverGetDomainCapabilities(virQEMUDriverPtr driver, > > domCaps = virHashSearch(domCapsCache, > > virQEMUDriverSearchDomcaps, &data, > > NULL); > > if (!domCaps) { > > + VIR_AUTOFREE(char *) key = NULL; > > + > > "g_autofree char *key = NULL;" instead of VIR_AUTOFREE for extra > karma > points. Everything else LGTM. > > > > Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com> > Looks good to me as well. But in keeping with the theme, we could also use g_strdup_printf() below instead of virAsprintf(). That is one of the suggestions made in the recent updates to our hacking documentation from Daniel's glib patch series. Reviewed-by: Jonathon Jongsma <jjongsma@redhat.com> > > > > /* hash miss, build new domcaps */ > > if (!(domCaps = virDomainCapsNew(data.path, data.machine, > > data.arch, > > data.virttype))) > > @@ -1406,7 +1408,14 @@ > > virQEMUDriverGetDomainCapabilities(virQEMUDriverPtr driver, > > cfg->firmwares, cfg- > > >nfirmwares) < 0) > > return NULL; > > > > - if (virHashAddEntry(domCapsCache, machine, domCaps) < 0) > > + if (virAsprintf(&key, "%d:%d:%s:%s", > > + data.arch, > > + data.virttype, > > + NULLSTR(data.machine), > > + NULLSTR(data.path)) < 0) > > + return NULL; > > + > > + if (virHashAddEntry(domCapsCache, key, domCaps) < 0) > > return NULL; > > } > > -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
On 10/16/19 12:22 PM, Jonathon Jongsma wrote: > On Wed, 2019-10-16 at 09:12 -0300, Daniel Henrique Barboza wrote: >> >> On 10/15/19 1:01 PM, Cole Robinson wrote: >>> When searching qemuCaps->domCapsCache for existing domCaps data, >>> we check for a matching pair of arch+virttype+machine+emulator. >>> However >>> for the hash table key we only use the machine string. So if the >>> cache already contains: >>> >>> x86_64 + kvm + pc + /usr/bin/qemu-kvm >>> >>> But a new VM is defined with >>> >>> x86_64 + qemu + pc + /usr/bin/qemu-kvm >>> >>> We correctly fail to find matching cached domCaps, but then attempt >>> to use a colliding key with virHashAddEntry >>> >>> Fix this by building a hash key from the 4 values, not just machine >>> >>> Signed-off-by: Cole Robinson <crobinso@redhat.com> >>> --- >>> qemu_domain.c validation should be affected, but it is covered up >>> by another bug, fixed here: >>> https://www.redhat.com/archives/libvir-list/2019-October/msg00708.html >>> >>> src/qemu/qemu_conf.c | 11 ++++++++++- >>> 1 file changed, 10 insertions(+), 1 deletion(-) >>> >>> diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c >>> index 08cd784054..64ac8cbdd3 100644 >>> --- a/src/qemu/qemu_conf.c >>> +++ b/src/qemu/qemu_conf.c >>> @@ -1396,6 +1396,8 @@ >>> virQEMUDriverGetDomainCapabilities(virQEMUDriverPtr driver, >>> domCaps = virHashSearch(domCapsCache, >>> virQEMUDriverSearchDomcaps, &data, >>> NULL); >>> if (!domCaps) { >>> + VIR_AUTOFREE(char *) key = NULL; >>> + >> >> "g_autofree char *key = NULL;" instead of VIR_AUTOFREE for extra >> karma >> points. Everything else LGTM. >> >> >> >> Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com> >> > > > Looks good to me as well. But in keeping with the theme, we could also > use g_strdup_printf() below instead of virAsprintf(). That is one of > the suggestions made in the recent updates to our hacking documentation > from Daniel's glib patch series. > > Reviewed-by: Jonathon Jongsma <jjongsma@redhat.com> > I decided to leave the virAsprintf as is, since it sounds like g_strdup_printf usage is in flux a bit and I figure there will be a mass conversion at some point. Thanks, Cole > >> >> >>> /* hash miss, build new domcaps */ >>> if (!(domCaps = virDomainCapsNew(data.path, data.machine, >>> data.arch, >>> data.virttype))) >>> @@ -1406,7 +1408,14 @@ >>> virQEMUDriverGetDomainCapabilities(virQEMUDriverPtr driver, >>> cfg->firmwares, cfg- >>>> nfirmwares) < 0) >>> return NULL; >>> >>> - if (virHashAddEntry(domCapsCache, machine, domCaps) < 0) >>> + if (virAsprintf(&key, "%d:%d:%s:%s", >>> + data.arch, >>> + data.virttype, >>> + NULLSTR(data.machine), >>> + NULLSTR(data.path)) < 0) >>> + return NULL; >>> + >>> + if (virHashAddEntry(domCapsCache, key, domCaps) < 0) >>> return NULL; >>> } >>> > - Cole -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c index 08cd784054..64ac8cbdd3 100644 --- a/src/qemu/qemu_conf.c +++ b/src/qemu/qemu_conf.c @@ -1396,6 +1396,8 @@ virQEMUDriverGetDomainCapabilities(virQEMUDriverPtr driver, domCaps = virHashSearch(domCapsCache, virQEMUDriverSearchDomcaps, &data, NULL); if (!domCaps) { + VIR_AUTOFREE(char *) key = NULL; + /* hash miss, build new domcaps */ if (!(domCaps = virDomainCapsNew(data.path, data.machine, data.arch, data.virttype))) @@ -1406,7 +1408,14 @@ virQEMUDriverGetDomainCapabilities(virQEMUDriverPtr driver, cfg->firmwares, cfg->nfirmwares) < 0) return NULL; - if (virHashAddEntry(domCapsCache, machine, domCaps) < 0) + if (virAsprintf(&key, "%d:%d:%s:%s", + data.arch, + data.virttype, + NULLSTR(data.machine), + NULLSTR(data.path)) < 0) + return NULL; + + if (virHashAddEntry(domCapsCache, key, domCaps) < 0) return NULL; }
When searching qemuCaps->domCapsCache for existing domCaps data, we check for a matching pair of arch+virttype+machine+emulator. However for the hash table key we only use the machine string. So if the cache already contains: x86_64 + kvm + pc + /usr/bin/qemu-kvm But a new VM is defined with x86_64 + qemu + pc + /usr/bin/qemu-kvm We correctly fail to find matching cached domCaps, but then attempt to use a colliding key with virHashAddEntry Fix this by building a hash key from the 4 values, not just machine Signed-off-by: Cole Robinson <crobinso@redhat.com> --- qemu_domain.c validation should be affected, but it is covered up by another bug, fixed here: https://www.redhat.com/archives/libvir-list/2019-October/msg00708.html src/qemu/qemu_conf.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) -- 2.23.0 -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list