Re: [libvirt] [PATCH v4 3/3] qemu: Automatically create NVRAM store

diff --git a/src/qemu/qemu.conf b/src/qemu/qemu.conf index 7bbbe09..79bba36 100644 --- a/src/qemu/qemu.conf +++ b/src/qemu/qemu.conf @@ -487,3 +487,17 @@ # Defaults to 1. # #log_timestamp = 0 + + +# Location of master nvram file +# +# When a domain is configured to use UEFI instead of standard +# BIOS it may use a separate storage for UEFI variables. If +# that's the case libvirt creates the variable store per domain +# using this master file as image. Each UEFI firmware can, +# however, have different variables store. Therefore the nvram is +# a list of strings when a single item is in form of: +# ${PATH_TO_UEFI_FW}:${PATH_TO_UEFI_VARS}. +# Later, when libvirt creates per domain variable store, this +# list is searched for the master image. +#nvram = [ "/usr/share/OVMF/OVMF_CODE.fd:/usr/share/OVMF/OVMF_VARS.fd" ]

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index baa866a..6f79a17 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -67,6 +67,7 @@ #include "virstring.h" #include "virhostdev.h" #include "storage/storage_driver.h" +#include "configmake.h" #define VIR_FROM_THIS VIR_FROM_QEMU @@ -3734,6 +3735,130 @@ qemuProcessVerifyGuestCPU(virQEMUDriverPtr driver, } +static int +qemuPrepareNVRAM(virQEMUDriverConfigPtr cfg, + virDomainDefPtr def, + bool migrated) +{ + int ret = -1; + int srcFD = -1; + int dstFD = -1; + virDomainLoaderDefPtr loader = def->os.loader; + bool generated = false; + bool created = false; + + /* Unless domain has RO loader of pflash type, we have + * nothing to do here. If the loader is RW then it's not + * using split code and vars feature, so no nvram file needs + * to be created. */ + if (!loader || loader->type != VIR_DOMAIN_LOADER_TYPE_PFLASH || + loader->readonly != VIR_TRISTATE_SWITCH_ON) + return 0; + + /* If the nvram path is configured already, there's nothing + * we need to do. Unless we are starting the destination side + * of migration in which case nvram is configured in the + * domain XML but the file doesn't exist yet. Moreover, after + * the migration is completed, qemu will invoke a + * synchronization write into the nvram file so we don't have + * to take care about transmitting the real data on the other + * side. */ + if (loader->nvram && !migrated) + return 0; + + /* Autogenerate nvram path if needed.*/ + if (!loader->nvram) { + if (virAsprintf(&loader->nvram, + "%s/lib/libvirt/qemu/nvram/%s_VARS.fd", + LOCALSTATEDIR, def->name) < 0) + goto cleanup;

+ + generated = true; + } + + if (!virFileExists(loader->nvram)) { + size_t i; + ssize_t r; + + for (i = 0; i < cfg->nloader; i++) { + if (STREQ(cfg->loader[i], loader->path)) + break; + } + + if (i == cfg->nloader) { + virReportError(VIR_ERR_OPERATION_FAILED, + _("unable to find any master var store for " + "loader: %s"), loader->path); + goto cleanup; + } + + if ((srcFD = virFileOpenAs(cfg->nvram[i], O_RDONLY, + 0, -1, -1, 0)) < 0) { + virReportSystemError(-srcFD, + _("Failed to open file '%s'"), + cfg->nvram[i]); + goto cleanup; + } + if ((dstFD = virFileOpenAs(loader->nvram, + O_WRONLY | O_CREAT | O_EXCL, + S_IRUSR | S_IWUSR, + cfg->user, cfg->group, 0)) < 0) { + virReportSystemError(-dstFD, + _("Failed to create file '%s'"), + loader->nvram); + goto cleanup; + } + created = true; + + do { + char buf[1024]; + + if ((r = saferead(srcFD, buf, sizeof(buf))) < 0) { + virReportSystemError(errno, + _("Unable to read from file '%s'"), + cfg->nvram[i]); + goto cleanup; + } + + if (safewrite(dstFD, buf, r) < 0) { + virReportSystemError(errno, + _("Unable to write to file '%s'"), + loader->nvram); + goto cleanup; + } + } while (r); + + if (VIR_CLOSE(srcFD) < 0) { + virReportSystemError(errno, + _("Unable to close file '%s'"), + cfg->nvram[i]); + goto cleanup; + } + if (VIR_CLOSE(dstFD) < 0) { + virReportSystemError(errno, + _("Unable to close file '%s'"), + loader->nvram); + goto cleanup; + } + } + + ret = 0; + cleanup: + /* We successfully generated the nvram path, but failed to + * copy the file content. Roll back. */ + if (ret < 0) { + if (created) + unlink(loader->nvram); + if (generated) + VIR_FREE(loader->nvram); + } + + VIR_FORCE_CLOSE(srcFD); + VIR_FORCE_CLOSE(dstFD); + return ret; +}