March 2022 - Devel - libvirt List Archives

[PATCH] virConnectDomainEventRegisterAny: correct docs
by John Levon 28 Mar '22

28 Mar '22

The callback ID can be zero, not necessarily positive; correct the comment to reflect this. Signed-off-by: John Levon <levon(a)movementarian.org> --- src/libvirt-domain.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c index a197618673..53efb60406 100644 --- a/src/libvirt-domain.c +++ b/src/libvirt-domain.c @@ -9486,7 +9486,7 @@ virDomainMigrateStartPostCopy(virDomainPtr domain, * The reference can be released once the object is no longer required * by calling virDomainFree(). * - * The return value from this method is a positive integer identifier + * The return value from this method is a non-negative integer identifier * for the callback. To unregister a callback, this callback ID should * be passed to the virConnectDomainEventDeregisterAny() method. * -- 2.32.0

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[PATCH] virfile: Report error when changing pipe size fails
by Michal Privoznik 28 Mar '22

28 Mar '22

When changing the size of pipe that virFileWrapperFdNew() creates we start at 1MiB and if that fails because it's above the system wide limit we get EPERM and continue with half of the size. However, we might get another error in which case we should report proper system error and return failure from virFileWrapperFdNew(). Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com> --- src/util/virfile.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/src/util/virfile.c b/src/util/virfile.c index 12b359d550..130b0fbace 100644 --- a/src/util/virfile.c +++ b/src/util/virfile.c @@ -217,7 +217,7 @@ struct _virFileWrapperFd { * * OS note: only for linux, on other OS this is a no-op. */ -static void +static int virFileWrapperSetPipeSize(int fd) { int sz; @@ -230,21 +230,24 @@ virFileWrapperSetPipeSize(int fd) continue; /* retry with half the size */ } if (rv < 0) { - break; + virReportSystemError(errno, "%s", + _("unable to set pipe size")); + return -1; } VIR_DEBUG("fd %d pipe size adjusted to %d", fd, sz); - return; + return 0; } VIR_WARN("unable to set pipe size, data transfer might be slow: %s", g_strerror(errno)); + return 0; } # else /* !__linux__ */ -static void +static int virFileWrapperSetPipeSize(int fd G_GNUC_UNUSED) { - return; + return 0; } # endif /* !__linux__ */ @@ -323,6 +326,9 @@ virFileWrapperFdNew(int *fd, const char *name, unsigned int flags) if (virPipe(pipefd) < 0) goto error; + if (virFileWrapperSetPipeSize(pipefd[output]) < 0) + goto error; + if (!(iohelper_path = virFileFindResource("libvirt_iohelper", abs_top_builddir "/src", LIBEXECDIR))) @@ -330,8 +336,6 @@ virFileWrapperFdNew(int *fd, const char *name, unsigned int flags) ret->cmd = virCommandNewArgList(iohelper_path, name, NULL); - virFileWrapperSetPipeSize(pipefd[output]); - if (output) { virCommandSetInputFD(ret->cmd, pipefd[0]); virCommandSetOutputFD(ret->cmd, fd); -- 2.34.1

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Request to move my GitLab custom executor repo under the libvirt umbrella
by Erik Skultety 28 Mar '22

28 Mar '22

So, we successfully enabled functional testing utilizing GitLab's custom executor feature. The code responsible for creating template images and provisioning and tearing down the VM workers currently lives under my GitLab account [1] and I think it would be better if we hosted it under the libvirt umbrella, especially since the project should serve as a uniform way of setting up custom runners for anyone in the libvirt community. If you think this is not a good idea, then please speak up and raise your concerns. Note there's still quite some work to be done with the project in general, but I'd be happy for any feedback in terms of what needs to be done prior moving the project to the libvirt namespace. Regards, Erik [1] https://gitlab.com/eskultety/libvirt-gitlab-executor

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[libvirt RFCv4] virfile: set pipe size in virFileWrapperFdNew to improve throughput
by Claudio Fontana 28 Mar '22

28 Mar '22

currently the only user of virFileWrapperFdNew is the qemu driver; virsh save is very slow with a default pipe size. This change improves throughput by ~400% on fast nvme or ramdisk. Best value currently measured is 1MB, which happens to be also the kernel default for the pipe-max-size. Signed-off-by: Claudio Fontana <cfontana(a)suse.de> --- src/util/virfile.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) see v2 at https://listman.redhat.com/archives/libvir-list/2022-March/229423.html Changes v3 -> v4: * changed INFO and WARN messages to DEBUG (Daniel) Changes v2 -> v3: * removed reading of max-pipe-size from procfs, instead make multiple attempts on EPERM with smaller sizes. In the regular case, this should succeed on the first try. (Daniel) Changes v1 -> v2: * removed VIR_FILE_WRAPPER_BIG_PIPE, made the new pipe resizing unconditional (Michal) * moved code to separate functions (Michal) * removed ternary op, disliked in libvirt (Michal) * added #ifdef __linux__ (Ani Sinha) * try smallest value between currently best measured value (1MB) and the pipe-max-size setting. If pipe-max-size cannot be read, try kernel default max (1MB). (Daniel) diff --git a/src/util/virfile.c b/src/util/virfile.c index a04f888e06..87539be0b9 100644 --- a/src/util/virfile.c +++ b/src/util/virfile.c @@ -201,6 +201,50 @@ struct _virFileWrapperFd { }; #ifndef WIN32 + +#ifdef __linux__ + +/** + * virFileWrapperSetPipeSize: + * @fd: the fd of the pipe + * + * Set best pipe size on the passed file descriptor for bulk transfers of data. + * + * default pipe size (usually 64K) is generally not suited for large transfers + * to fast devices. A value of 1MB has been measured to improve virsh save + * by 400% in ideal conditions. We retry multiple times with smaller sizes + * on EPERM to account for possible small values of /proc/sys/fs/pipe-max-size. + * + * OS note: only for linux, on other OS this is a no-op. + */ +static void +virFileWrapperSetPipeSize(int fd) +{ + int sz; + + for (sz = 1024 * 1024; sz >= 64 * 1024; sz /= 2) { + int rv = fcntl(fd, F_SETPIPE_SZ, sz); + if (rv < 0 && errno == EPERM) { + VIR_DEBUG("EPERM trying to set fd %d pipe size to %d", fd, sz); + continue; /* retry with half the size */ + } + if (rv < 0) { + break; + } + VIR_DEBUG("fd %d pipe size adjusted to %d", fd, sz); + return; + } + virReportSystemError(errno, "%s", _("unable to set pipe size, data transfer might be slow")); +} + +#else /* !__linux__ */ +static void virFileWrapperSetPipeSize(int fd) +{ + return; +} +#endif /* !__linux__ */ + + /** * virFileWrapperFdNew: * @fd: pointer to fd to wrap @@ -282,6 +326,8 @@ virFileWrapperFdNew(int *fd, const char *name, unsigned int flags) ret->cmd = virCommandNewArgList(iohelper_path, name, NULL); + virFileWrapperSetPipeSize(pipefd[!output]); + if (output) { virCommandSetInputFD(ret->cmd, pipefd[0]); virCommandSetOutputFD(ret->cmd, fd); -- 2.35.1

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[build-fix PATCH] util: virfile: Fix indentation of preprocessor directives
by Peter Krempa 28 Mar '22

28 Mar '22

stderr: cppi: /home/pipo/libvirt/src/util/virfile.c: line 205: not properly indented cppi: /home/pipo/libvirt/src/util/virfile.c: line 243: not properly indented cppi: /home/pipo/libvirt/src/util/virfile.c: line 249: not properly indented build-aux/syntax-check.mk: incorrect preprocessor indentation make: *** [/home/pipo/libvirt/build-aux/syntax-check.mk:565: sc_preprocessor_indentation] Error 1 Fixes: c61d1e9ba0a0bec18fdb0bdd485060dc27a4e5cc Signed-off-by: Peter Krempa <pkrempa(a)redhat.com> --- Pushed. src/util/virfile.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/src/util/virfile.c b/src/util/virfile.c index 6f2af35201..12b359d550 100644 --- a/src/util/virfile.c +++ b/src/util/virfile.c @@ -202,7 +202,7 @@ struct _virFileWrapperFd { #ifndef WIN32 -#ifdef __linux__ +# ifdef __linux__ /** * virFileWrapperSetPipeSize: @@ -240,13 +240,13 @@ virFileWrapperSetPipeSize(int fd) g_strerror(errno)); } -#else /* !__linux__ */ +# else /* !__linux__ */ static void virFileWrapperSetPipeSize(int fd G_GNUC_UNUSED) { return; } -#endif /* !__linux__ */ +# endif /* !__linux__ */ /** -- 2.35.1

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[PATCH v2 0/6] qemu: Add qemu-namespace XML to override device properties (-set replacement)
by Peter Krempa 28 Mar '22

28 Mar '22

v2: - patch 1/7 from last time was pushed - XML changes: - top level element renamed to "qemu:override" to accomodate possible extension in the future - wrapped 'qemu:props' meant to override the frontend under a 'qemu:frontend' element - code changes: - renamed few bits (dropped 'Device') from code that can theoretically be reused - split out some functions for enhanced extensibility in the future Peter Krempa (6): docs: drvqemu: Document overriding of device properties qemu: domain: Add XML namespace code for overriding device config conf: Introduce VIR_DOMAIN_TAINT_CUSTOM_DEVICE and use it in qemu qemuBuildDeviceCommandlineFromJSON: Pass 'virDomainDef' into the function qemu: command: Override device definition according to the namespace config NEWS: Mention the qemu device property override feature NEWS.rst | 7 + docs/drvqemu.rst | 57 +++++ src/conf/domain_conf.c | 2 + src/conf/domain_conf.h | 1 + src/conf/schemas/domaincommon.rng | 42 ++++ src/qemu/qemu_command.c | 133 +++++++---- src/qemu/qemu_domain.c | 221 ++++++++++++++++++ src/qemu/qemu_domain.h | 33 +++ .../qemu-ns.x86_64-4.0.0.args | 2 +- .../qemu-ns.x86_64-latest.args | 2 +- tests/qemuxml2argvdata/qemu-ns.xml | 14 ++ .../qemu-ns.x86_64-latest.xml | 14 ++ 12 files changed, 478 insertions(+), 50 deletions(-) -- 2.35.1

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[PATCH 0/2] Revert two patches I've pushed mistakenly
by Michal Privoznik 28 Mar '22

28 Mar '22

Firstly, QEMU part is not merged which alone should have prevented me from pushing these patches. Secondly, in the end QEMU is fixing the bug in a different manner that does not require any libvirt work. https://lists.gnu.org/archive/html/qemu-devel/2022-03/msg06077.html https://lists.gnu.org/archive/html/qemu-devel/2022-03/msg06188.html Michal Prívozník (2): Revert "domain: add tsc.on_reboot element" Revert "qemu: add support for tsc.on_reboot element" docs/formatdomain.rst | 4 -- src/conf/domain_conf.c | 17 ------- src/conf/domain_conf.h | 10 ----- src/conf/schemas/domaincommon.rng | 8 ---- src/qemu/qemu_capabilities.c | 2 - src/qemu/qemu_capabilities.h | 1 - src/qemu/qemu_command.c | 11 ----- src/qemu/qemu_validate.c | 45 ++++++++----------- .../caps_7.0.0.x86_64.replies | 4 -- .../caps_7.0.0.x86_64.xml | 1 - .../cpu-tsc-clear-on-reset.args | 32 ------------- .../cpu-tsc-clear-on-reset.x86_64-7.0.0.args | 34 -------------- .../cpu-tsc-clear-on-reset.xml | 35 --------------- tests/qemuxml2argvtest.c | 2 - 14 files changed, 19 insertions(+), 187 deletions(-) delete mode 100644 tests/qemuxml2argvdata/cpu-tsc-clear-on-reset.args delete mode 100644 tests/qemuxml2argvdata/cpu-tsc-clear-on-reset.x86_64-7.0.0.args delete mode 100644 tests/qemuxml2argvdata/cpu-tsc-clear-on-reset.xml -- 2.34.1

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[PATCH v2 0/7] Do async IO when starting swtpm emulator
by Michal Privoznik 28 Mar '22

28 Mar '22

v2 of: https://listman.redhat.com/archives/libvir-list/2022-March/229433.html diff to v1: - More fixes - New test case, yay! Michal Prívozník (7): qemu_tpm: Do async IO when starting swtpm emulator vircommand: Document virCommandSetSendBuffer() behaviour wrt daemonize vircommand: Don't set nonblocking FDs in virCommandDoAsyncIO() commandtest: Use unsigned char in test27() virCommandSetSendBuffer: Take double pointer of @buffer commandtest: Test virCommandSetSendBuffer() with virCommandDoAsyncIO() commandtest: Use virTestCompareToFile() in checkoutput() src/qemu/qemu_tpm.c | 3 +- src/util/vircommand.c | 12 ++-- src/util/vircommand.h | 2 +- tests/commanddata/test29.log | 19 ++++++ tests/commandtest.c | 110 +++++++++++++++++++++++++++++------ 5 files changed, 121 insertions(+), 25 deletions(-) create mode 100644 tests/commanddata/test29.log -- 2.34.1

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[PATCH 0/2] domain, qemu: add support for clearing TSC on reset
by Paolo Bonzini 28 Mar '22

28 Mar '22

Some versions of Windows hang on reboot if their TSC value is greater than 2^54. The workaround is to reset the TSC to a small value, and is implemented by QEMU and ESXi. This series adds a domain attribute for this, and implements it in QEMU. Paolo Paolo Bonzini (2): domain: add tsc.on_reboot element qemu: add support for tsc.on_reboot element docs/formatdomain.rst | 4 +++ src/conf/domain_conf.c | 22 ++++++++++++ src/conf/domain_conf.h | 10 ++++++ src/conf/schemas/domaincommon.rng | 9 +++++ src/qemu/qemu_capabilities.c | 2 ++ src/qemu/qemu_capabilities.h | 1 + src/qemu/qemu_command.c | 4 +++ src/qemu/qemu_validate.c | 36 +++++++++++++------ .../caps_7.0.0.x86_64.replies | 4 +++ .../caps_7.0.0.x86_64.xml | 1 + ...uency.args => cpu-tsc-clear-on-reset.args} | 2 +- ... cpu-tsc-clear-on-reset.x86_64-7.0.0.args} | 6 ++-- ...equency.xml => cpu-tsc-clear-on-reset.xml} | 2 +- tests/qemuxml2argvtest.c | 2 ++ 14 files changed, 89 insertions(+), 16 deletions(-) copy tests/qemuxml2argvdata/{cpu-tsc-frequency.args => cpu-tsc-clear-on-reset.args} (97%) copy tests/qemuxml2argvdata/{virtio-rng-builtin.x86_64-latest.args => cpu-tsc-clear-on-reset.x86_64-7.0.0.args} (77%) copy tests/qemuxml2argvdata/{cpu-tsc-frequency.xml => cpu-tsc-clear-on-reset.xml} (95%) -- 2.35.1

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[libvirt PATCH] iohelper: some refactoring
by Claudio Fontana 27 Mar '22

27 Mar '22

while doing research with alternative implementations of runIO, it seemed necessary to do some refactoring, in order to separate parameter setting from the actual copy, so that alternative copy methods can be researched and hopefully eventually implemented. No functional changes are expected. Signed-off-by: Claudio Fontana <cfontana(a)suse.de> --- src/util/iohelper.c | 193 +++++++++++++++++++++++++++----------------- 1 file changed, 118 insertions(+), 75 deletions(-) diff --git a/src/util/iohelper.c b/src/util/iohelper.c index 2c91bf4f93..c04c97af27 100644 --- a/src/util/iohelper.c +++ b/src/util/iohelper.c @@ -45,21 +45,38 @@ # define O_DIRECT 0 #endif -static int -runIO(const char *path, int fd, int oflags) +struct runIOParams { + bool isBlockDev; + bool isDirect; + bool isWrite; + int fdin; + const char *fdinname; + int fdout; + const char *fdoutname; +}; + +/* runIOCopy: execute the IO copy based on the passed parameters */ +/** + * runIOCopy: + * @p: the IO parameters + * + * Execute the copy based on the passed parameters. + * + * Returns: size transfered, or < 0 on error. + * Errors: -1 = read/write error + * -2 = read error + * -3 = write error + * -4 = truncate error + */ + +static ssize_t +runIOCopy(const struct runIOParams p) { g_autofree void *base = NULL; /* Location to be freed */ char *buf = NULL; /* Aligned location within base */ size_t buflen = 1024*1024; intptr_t alignMask = 64*1024 - 1; - int ret = -1; - int fdin, fdout; - const char *fdinname, *fdoutname; - unsigned long long total = 0; - bool direct = O_DIRECT && ((oflags & O_DIRECT) != 0); - off_t end = 0; - struct stat sb; - bool isBlockDev = false; + ssize_t total = 0; #if WITH_POSIX_MEMALIGN if (posix_memalign(&base, alignMask + 1, buflen)) @@ -71,50 +88,6 @@ runIO(const char *path, int fd, int oflags) buf = (char *) (((intptr_t) base + alignMask) & ~alignMask); #endif - if (fstat(fd, &sb) < 0) { - virReportSystemError(errno, - _("Unable to access file descriptor %d path %s"), - fd, path); - goto cleanup; - } - isBlockDev = S_ISBLK(sb.st_mode); - - switch (oflags & O_ACCMODE) { - case O_RDONLY: - fdin = fd; - fdinname = path; - fdout = STDOUT_FILENO; - fdoutname = "stdout"; - /* To make the implementation simpler, we give up on any - * attempt to use O_DIRECT in a non-trivial manner. */ - if (!isBlockDev && direct && ((end = lseek(fd, 0, SEEK_CUR)) != 0)) { - virReportSystemError(end < 0 ? errno : EINVAL, "%s", - _("O_DIRECT read needs entire seekable file")); - goto cleanup; - } - break; - case O_WRONLY: - fdin = STDIN_FILENO; - fdinname = "stdin"; - fdout = fd; - fdoutname = path; - /* To make the implementation simpler, we give up on any - * attempt to use O_DIRECT in a non-trivial manner. */ - if (!isBlockDev && direct && (end = lseek(fd, 0, SEEK_END)) != 0) { - virReportSystemError(end < 0 ? errno : EINVAL, "%s", - _("O_DIRECT write needs empty seekable file")); - goto cleanup; - } - break; - - case O_RDWR: - default: - virReportSystemError(EINVAL, - _("Unable to process file with flags %d"), - (oflags & O_ACCMODE)); - goto cleanup; - } - while (1) { ssize_t got; @@ -124,53 +97,123 @@ runIO(const char *path, int fd, int oflags) * writes will be aligned. * In other cases using saferead reduces number of syscalls. */ - if (fdin == fd && direct) { - if ((got = read(fdin, buf, buflen)) < 0 && + if (!p.isWrite && p.isDirect) { + if ((got = read(p.fdin, buf, buflen)) < 0 && errno == EINTR) continue; } else { - got = saferead(fdin, buf, buflen); - } - - if (got < 0) { - virReportSystemError(errno, _("Unable to read %s"), fdinname); - goto cleanup; + got = saferead(p.fdin, buf, buflen); } + if (got < 0) + return -2; if (got == 0) break; total += got; /* handle last write size align in direct case */ - if (got < buflen && direct && fdout == fd) { + if (got < buflen && p.isDirect && p.isWrite) { ssize_t aligned_got = (got + alignMask) & ~alignMask; memset(buf + got, 0, aligned_got - got); - if (safewrite(fdout, buf, aligned_got) < 0) { - virReportSystemError(errno, _("Unable to write %s"), fdoutname); - goto cleanup; + if (safewrite(p.fdout, buf, aligned_got) < 0) { + return -3; } - - if (!isBlockDev && ftruncate(fd, total) < 0) { - virReportSystemError(errno, _("Unable to truncate %s"), fdoutname); - goto cleanup; + if (!p.isBlockDev && ftruncate(p.fdout, total) < 0) { + return -4; } - break; } + } + return total; +} - if (safewrite(fdout, buf, got) < 0) { - virReportSystemError(errno, _("Unable to write %s"), fdoutname); +static int +runIO(const char *path, int fd, int oflags) +{ + int ret = -1; + off_t total = 0; + struct stat sb; + struct runIOParams p; + + if (fstat(fd, &sb) < 0) { + virReportSystemError(errno, + _("Unable to access file descriptor %d path %s"), + fd, path); + goto cleanup; + } + p.isBlockDev = S_ISBLK(sb.st_mode); + p.isDirect = O_DIRECT && (oflags & O_DIRECT); + + switch (oflags & O_ACCMODE) { + case O_RDONLY: + p.isWrite = false; + p.fdin = fd; + p.fdinname = path; + p.fdout = STDOUT_FILENO; + p.fdoutname = "stdout"; + break; + case O_WRONLY: + p.isWrite = true; + p.fdin = STDIN_FILENO; + p.fdinname = "stdin"; + p.fdout = fd; + p.fdoutname = path; + break; + case O_RDWR: + default: + virReportSystemError(EINVAL, + _("Unable to process file with flags %d"), + (oflags & O_ACCMODE)); + goto cleanup; + } + /* To make the implementation simpler, we give up on any + * attempt to use O_DIRECT in a non-trivial manner. */ + if (!p.isBlockDev && p.isDirect) { + off_t end; + if (p.isWrite) { + if ((end = lseek(fd, 0, SEEK_END)) != 0) { + virReportSystemError(end < 0 ? errno : EINVAL, "%s", + _("O_DIRECT write needs empty seekable file")); + goto cleanup; + } + } else if ((end = lseek(fd, 0, SEEK_CUR)) != 0) { + virReportSystemError(end < 0 ? errno : EINVAL, "%s", + _("O_DIRECT read needs entire seekable file")); goto cleanup; } } + total = runIOCopy(p); + + if (total < 0) { + switch (total) { + case -1: + virReportSystemError(errno, _("Unable to move data from %s to %s"), + p.fdinname, p.fdoutname); + break; + case -2: + virReportSystemError(errno, _("Unable to read %s"), p.fdinname); + break; + case -3: + virReportSystemError(errno, _("Unable to write %s"), p.fdoutname); + break; + case -4: + virReportSystemError(errno, _("Unable to truncate %s"), p.fdoutname); + break; + default: + virReportError(VIR_ERR_INTERNAL_ERROR, _("Unknown runIOCopy error %ld"), total); + break; + } + goto cleanup; + } + /* Ensure all data is written */ - if (virFileDataSync(fdout) < 0) { + if (virFileDataSync(p.fdout) < 0) { if (errno != EINVAL && errno != EROFS) { /* fdatasync() may fail on some special FDs, e.g. pipes */ - virReportSystemError(errno, _("unable to fsync %s"), fdoutname); + virReportSystemError(errno, _("unable to fsync %s"), p.fdoutname); goto cleanup; } } -- 2.35.1

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