Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> --- CC: Jan Beulich <JBeulich@suse.com> CC: Roger Pau Monné <roger.pau@citrix.com> CC: Teddy Astie <teddy.astie@vates.tech> RFC. The docs update are rather nasy, and will take longer than I have right now. --- xen/arch/x86/cpu/microcode/core.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/cpu/microcode/core.c b/xen/arch/x86/cpu/microcode/core.c index XXXXXXX..XXXXXXX 100644 --- a/xen/arch/x86/cpu/microcode/core.c +++ b/xen/arch/x86/cpu/microcode/core.c @@ -XXX,XX +XXX,XX @@ static int __init early_microcode_load(struct boot_info *bi) void *data = NULL; size_t size; struct microcode_patch *patch; + struct cpio_data cd; int idx = opt_mod_idx; int rc; @@ -XXX,XX +XXX,XX @@ static int __init early_microcode_load(struct boot_info *bi) for ( idx = 0; idx < bi->nr_modules; ++idx ) { const struct boot_module *bm = &bi->mods[idx]; - struct cpio_data cd; /* Search anything unclaimed or likely to be a CPIO archive. */ if ( bm->kind != BOOTMOD_UNKNOWN && bm->kind != BOOTMOD_RAMDISK ) @@ -XXX,XX +XXX,XX @@ static int __init early_microcode_load(struct boot_info *bi) idx, size); return -ENODEV; } + + /* + * If this blob appears to be a CPIO archive, try interpreting it as + * one. Otherwise treat it as a raw vendor blob. + */ + cd = find_cpio_data(ucode_ops.cpio_path, data, size); + if ( cd.data ) + { + data = cd.data; + size = cd.size; + } + goto found; } base-commit: 18e255253a5a326deff0ade386e36d7965164533 -- 2.39.5 Multiple downstream distros have tried passing discrete CPIO archives and tripped over this not working. It turns out to be easy to support, so do so. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> --- CC: Jan Beulich <JBeulich@suse.com> CC: Roger Pau Monné <roger.pau@citrix.com> CC: Teddy Astie <teddy.astie@vates.tech> v2: * Docs update too. * Set opt_scan in early_microcode_load() so microcode_init_cache() operates properly --- CHANGELOG.md | 1 + docs/misc/xen-command-line.pandoc | 19 ++++++++----------- xen/arch/x86/cpu/microcode/core.c | 20 +++++++++++++++++++- 3 files changed, 28 insertions(+), 12 deletions(-) diff --git a/CHANGELOG.md b/CHANGELOG.md index XXXXXXX..XXXXXXX 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -XXX,XX +XXX,XX @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) - Support for Bus Lock Threshold on AMD Zen5 and later CPUs, used by Xen to mitigate (by rate-limiting) the system wide impact of an HVM guest misusing atomic instructions. + - Support for CPIO microcode in discrete multiboot modules. ### Removed - On x86: diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line.pandoc index XXXXXXX..XXXXXXX 100644 --- a/docs/misc/xen-command-line.pandoc +++ b/docs/misc/xen-command-line.pandoc @@ -XXX,XX +XXX,XX @@ Controls for CPU microcode loading, available when `CONFIG_MICROCODE_LOADING` is enabled. In order to load microcode at boot, Xen needs to find a suitable update -amongst the modules provided by the bootloader. Two kinds of microcode update -are supported: +amongst the modules provided by the bootloader. Two formats are supported: 1. Raw microcode containers. The format of the container is CPU vendor specific. - 2. CPIO archive. This is Linux's preferred mechanism, and involves having - the raw containers expressed as files + 2. CPIO archive, which involves having the raw containers expressed as files (e.g. `kernel/x86/microcode/{GenuineIntel,AuthenticAMD}.bin`) in a CPIO - archive, typically prepended to the initrd. + archive. Linux commonly prepends this to the initrd. -The `<integer>` and `scan=<bool>` options are mutually exclusive and select -between these two options. Further restrictions exist for booting xen.efi -(see below). +The `<integer>` and `scan=<bool>` options are mutually exclusive and work as +follows. Further restrictions exist for booting xen.efi (see below). - * The `<integer>` option nominates a specific multiboot module as a raw - container (option 1 above). Valid options start from 1 (module 0 is + * The `<integer>` option nominates a specific multiboot module as containing + microcode in either format. Valid options start from 1 (module 0 is always the dom0 kernel). A negative number may be used, and will back-reference from the end of the module list. i.e. `ucode=-1` will nominate the final multiboot module. @@ -XXX,XX +XXX,XX @@ When booting xen.efi natively, the concept of multiboot modules doesn't exist. Instead: * In the [EFI configuration file](efi.html), `ucode=<filename>` can be used - to identify a file as a raw container (option 1 above). Use of this + to identify a file as containing microcode in either format. Use of this mechanism will disable both `<integer>` and `scan=`. * If `ucode=<filename>` in the EFI configuration file is not used, it is diff --git a/xen/arch/x86/cpu/microcode/core.c b/xen/arch/x86/cpu/microcode/core.c index XXXXXXX..XXXXXXX 100644 --- a/xen/arch/x86/cpu/microcode/core.c +++ b/xen/arch/x86/cpu/microcode/core.c @@ -XXX,XX +XXX,XX @@ static int __init early_microcode_load(struct boot_info *bi) void *data = NULL; size_t size; const struct microcode_patch *patch; + struct cpio_data cd; int idx = opt_mod_idx; int rc; @@ -XXX,XX +XXX,XX @@ static int __init early_microcode_load(struct boot_info *bi) for ( idx = 0; idx < bi->nr_modules; ++idx ) { const struct boot_module *bm = &bi->mods[idx]; - struct cpio_data cd; /* Search anything unclaimed or likely to be a CPIO archive. */ if ( bm->kind != BOOTMOD_UNKNOWN && bm->kind != BOOTMOD_RAMDISK ) @@ -XXX,XX +XXX,XX @@ static int __init early_microcode_load(struct boot_info *bi) idx, size); return -ENODEV; } + + /* + * If this blob appears to be a CPIO archive, try interpreting it as + * one. Otherwise treat it as a raw vendor blob. + */ + cd = find_cpio_data(ucode_ops.cpio_path, data, size); + if ( cd.data ) + { + data = cd.data; + size = cd.size; + + /* + * (Ab)use opt_scan to inform microcode_init_cache() that + * early_mod_idx refers to a CPIO archive. + */ + opt_scan = true; + } + goto found; } base-commit: 5eb84d6c992cf4e81936872c441b649057947442 -- 2.39.5