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([185.25.67.249]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5ac63590e7esm558590a12.36.2024.07.25.01.27.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 25 Jul 2024 01:27:52 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: c98fceed-4a5f-11ef-bbff-fd08da9f4363 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloud.com; s=cloud; t=1721896073; x=1722500873; darn=lists.xenproject.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=VVOe/t8VUEI4RbQ7J8nQRfJ3cqYvw3XGeBz8W3XqdYQ=; b=bc9NLOZqY8akKdVl6epvNFAIRbhXk37XuqogVZYvHCD0CfcZLQcXrWX1RyuO6QR8fm 6jTsaw3Wb2m9Cbt+GwD8RKQkbIIw4L8fGTlZ1yBqPFu/tAUwRMyfHka1VMfunAWkKWTL qeYJcHFQgvi/n5+Yio6780R1x8OI2yQWZbDpc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721896073; x=1722500873; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=VVOe/t8VUEI4RbQ7J8nQRfJ3cqYvw3XGeBz8W3XqdYQ=; b=m8tPmJP5acrqNOFpLaVCWEM/EGXH9GVviiVVARrMArM28FuCr9FWY6WhUFZTWqdP0a ujnRyAlKcdinkAFwzNT50FFi+zFDQncxf4tNn6eGzz2raUsmAqUUJF8pcCnnhgoAjJts CIiGxLtpqf4qI6iXAfzwO2DrbBX9KouZOzYm9U4MIUBl9ztW45h9zxW6kUHKNpmqByc4 31mJJFbkoXOHMi9M0vRCTnry7vvjUdgeSfBKkiVUjGxseDBOIfYauB1PZH8HUdNida/b 3nzzM+jks2oiJ257zF3tN2poKkaP3DAP9TZNX8SVsa1ItC0eiCCGbHHoAfQvdgoaz7+q g1qQ== X-Gm-Message-State: AOJu0YyBD7wSEF8wksHNYRBuunZ5YyUm+xO5cf6Xz14xvFMYsABaop9A +AnIJ/yegB9a/zn9SOYHny6vvgvDNWS4HAMyTkl4ZdbW6oFEuLkXys2EinBdyUAwOmWVCIErLQs z X-Google-Smtp-Source: AGHT+IHqduZ9jVdHIHCAMWvCZqNZx+lg5p4II0Cave3jH/z3mA1k0t7L04M1v0i9O+J7YkYuM9Katw== X-Received: by 2002:a50:870b:0:b0:58b:9561:650b with SMTP id 4fb4d7f45d1cf-5ac63c50f88mr962304a12.25.1721896072638; Thu, 25 Jul 2024 01:27:52 -0700 (PDT) From: Fouad Hilly To: xen-devel@lists.xenproject.org Cc: Fouad Hilly , Andrew Cooper , Jan Beulich , Julien Grall , Stefano Stabellini , =?utf-8?q?Roger_Pau_Monn=C3=A9?= Subject: [PATCH v6 4/4] x86/ucode: Utilize ucode_force and remove opt_ucode_allow_same Date: Thu, 25 Jul 2024 09:27:25 +0100 Message-ID: <20240725082725.2685481-5-fouad.hilly@cloud.com> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20240725082725.2685481-1-fouad.hilly@cloud.com> References: <20240725082725.2685481-1-fouad.hilly@cloud.com> MIME-Version: 1.0 Pass xen-ucode flags to do low level checks on micorocde version and utilize it to allow for microcode downgrade or reapply the same version of the microcode. ucode_force is required to be passed to a low level Intel and AMD for version checks to be done. While adding ucode_force, opt_ucode_allow_same was removed. Remove opt_ucode_allow_same from documentation. Signed-off-by: Fouad Hilly --- [v6] 1- Removed struct microcode_nmi_patch_with_flags. 2- removed const from control_thread_fn() and primary_thread_fn(). 3- Fixed "flags" checks. [v5] 1- Update commit message. 2- Introduce structs microcode_patch_with_flags and microcode_nmi_patch_with_flags. 3- pass flags to Intel and AMD low level through apply_microcode(). [4] 1- As opt_ucode_allow_same is not required anymore, it has been removed while introducing ucode_force. 2- Apply the changes for both AMD and Intel. 3- Remove the mention of opt_ucode_allow_same from documentation. --- docs/misc/xen-command-line.pandoc | 7 +-- xen/arch/x86/cpu/microcode/amd.c | 8 ++- xen/arch/x86/cpu/microcode/core.c | 88 +++++++++++++++++----------- xen/arch/x86/cpu/microcode/intel.c | 9 ++- xen/arch/x86/cpu/microcode/private.h | 5 +- 5 files changed, 68 insertions(+), 49 deletions(-) diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line.pandoc index 98a45211556b..2a8d47bbc664 100644 --- a/docs/misc/xen-command-line.pandoc +++ b/docs/misc/xen-command-line.pandoc @@ -2650,7 +2650,7 @@ performance. Alternatively, selecting `tsx=1` will re-enable TSX at the users own risk. ### ucode -> `= List of [ | scan=, nmi=, allow-same= ]` +> `= List of [ | scan=, nmi= ]` Applicability: x86 Default: `nmi` @@ -2682,11 +2682,6 @@ precedence over `scan`. stop_machine context. In NMI handler, even NMIs are blocked, which is considered safer. The default value is `true`. -'allow-same' alters the default acceptance policy for new microcode to permit -trying to reload the same version. Many CPUs will actually reload microcode -of the same version, and this allows for easy testing of the late microcode -loading path. - ### unrestricted_guest (Intel) > `= ` diff --git a/xen/arch/x86/cpu/microcode/amd.c b/xen/arch/x86/cpu/microcode/amd.c index f76a563c8b84..80ff6335d64a 100644 --- a/xen/arch/x86/cpu/microcode/amd.c +++ b/xen/arch/x86/cpu/microcode/amd.c @@ -22,6 +22,8 @@ #include "private.h" +#include "public/platform.h" + #define pr_debug(x...) ((void)0) struct equiv_cpu_entry { @@ -214,13 +216,15 @@ static enum microcode_match_result cf_check compare_patch( return compare_header(new, old); } -static int cf_check apply_microcode(const struct microcode_patch *patch) +static int cf_check apply_microcode(const struct microcode_patch *patch, + unsigned int flags) { int hw_err; unsigned int cpu = smp_processor_id(); struct cpu_signature *sig = &per_cpu(cpu_sig, cpu); uint32_t rev, old_rev = sig->rev; enum microcode_match_result result = microcode_fits(patch); + bool ucode_force = flags & XENPF_UCODE_FORCE; if ( result == MIS_UCODE ) return -EINVAL; @@ -229,7 +233,7 @@ static int cf_check apply_microcode(const struct microcode_patch *patch) * Allow application of the same revision to pick up SMT-specific changes * even if the revision of the other SMT thread is already up-to-date. */ - if ( result == OLD_UCODE ) + if ( !ucode_force && (result == SAME_UCODE || result == OLD_UCODE) ) return -EEXIST; if ( check_final_patch_levels(sig) ) diff --git a/xen/arch/x86/cpu/microcode/core.c b/xen/arch/x86/cpu/microcode/core.c index 8a9e744489b9..a0106a987e33 100644 --- a/xen/arch/x86/cpu/microcode/core.c +++ b/xen/arch/x86/cpu/microcode/core.c @@ -90,6 +90,11 @@ struct ucode_mod_blob { size_t size; }; +struct patch_with_flags { + unsigned int flags; + struct microcode_patch *patch; +}; + static struct ucode_mod_blob __initdata ucode_blob; /* * By default we will NOT parse the multiboot modules to see if there is @@ -100,8 +105,6 @@ static bool __initdata ucode_scan; /* By default, ucode loading is done in NMI handler */ static bool ucode_in_nmi = true; -bool __read_mostly opt_ucode_allow_same; - /* Protected by microcode_mutex */ static struct microcode_patch *microcode_cache; @@ -128,8 +131,6 @@ static int __init cf_check parse_ucode(const char *s) if ( (val = parse_boolean("nmi", s, ss)) >= 0 ) ucode_in_nmi = val; - else if ( (val = parse_boolean("allow-same", s, ss)) >= 0 ) - opt_ucode_allow_same = val; else if ( !ucode_mod_forced ) /* Not forced by EFI */ { if ( (val = parse_boolean("scan", s, ss)) >= 0 ) @@ -237,7 +238,11 @@ static DEFINE_PER_CPU(int, loading_err); */ static cpumask_t cpu_callin_map; static atomic_t cpu_out, cpu_updated; -static const struct microcode_patch *nmi_patch = ZERO_BLOCK_PTR; +static struct patch_with_flags nmi_patch_with_flags = +{ + .flags = 0, + .patch = ZERO_BLOCK_PTR, +}; /* * Return a patch that covers current CPU. If there are multiple patches, @@ -327,7 +332,8 @@ static bool cf_check wait_cpu_callout(unsigned int nr) * If no patch is provided, the cached patch will be loaded. Microcode update * during APs bringup and CPU resuming falls into this case. */ -static int microcode_update_cpu(const struct microcode_patch *patch) +static int microcode_update_cpu(const struct microcode_patch *patch, + unsigned int flags) { int err; @@ -335,10 +341,11 @@ static int microcode_update_cpu(const struct microcode_patch *patch) spin_lock(µcode_mutex); if ( patch ) - err = alternative_call(ucode_ops.apply_microcode, patch); + err = alternative_call(ucode_ops.apply_microcode, patch, flags); else if ( microcode_cache ) { - err = alternative_call(ucode_ops.apply_microcode, microcode_cache); + err = alternative_call(ucode_ops.apply_microcode, microcode_cache, + flags); if ( err == -EIO ) { microcode_free_patch(microcode_cache); @@ -379,7 +386,8 @@ static int secondary_nmi_work(void) return wait_for_state(LOADING_EXIT) ? 0 : -EBUSY; } -static int primary_thread_work(const struct microcode_patch *patch) +static int primary_thread_work(struct microcode_patch *patch, + unsigned int flags) { int ret; @@ -388,7 +396,7 @@ static int primary_thread_work(const struct microcode_patch *patch) if ( !wait_for_state(LOADING_ENTER) ) return -EBUSY; - ret = alternative_call(ucode_ops.apply_microcode, patch); + ret = alternative_call(ucode_ops.apply_microcode, patch, flags); if ( !ret ) atomic_inc(&cpu_updated); atomic_inc(&cpu_out); @@ -416,7 +424,8 @@ static int cf_check microcode_nmi_callback( return 0; if ( primary_cpu ) - ret = primary_thread_work(nmi_patch); + ret = primary_thread_work(nmi_patch_with_flags.patch, + nmi_patch_with_flags.flags); else ret = secondary_nmi_work(); this_cpu(loading_err) = ret; @@ -446,7 +455,8 @@ static int secondary_thread_fn(void) return this_cpu(loading_err); } -static int primary_thread_fn(const struct microcode_patch *patch) +static int primary_thread_fn(struct microcode_patch *patch, + unsigned int flags) { if ( !wait_for_state(LOADING_CALLIN) ) return -EBUSY; @@ -466,10 +476,11 @@ static int primary_thread_fn(const struct microcode_patch *patch) return this_cpu(loading_err); } - return primary_thread_work(patch); + return primary_thread_work(patch, flags); } -static int control_thread_fn(const struct microcode_patch *patch) +static int control_thread_fn(struct microcode_patch *patch, + unsigned int flags) { unsigned int cpu = smp_processor_id(), done; unsigned long tick; @@ -482,7 +493,8 @@ static int control_thread_fn(const struct microcode_patch *patch) */ watchdog_disable(); - nmi_patch = patch; + nmi_patch_with_flags.patch = patch; + nmi_patch_with_flags.flags = flags; smp_wmb(); saved_nmi_callback = set_nmi_callback(microcode_nmi_callback); @@ -498,7 +510,7 @@ static int control_thread_fn(const struct microcode_patch *patch) goto out; /* Control thread loads ucode first while others are in NMI handler. */ - ret = alternative_call(ucode_ops.apply_microcode, patch); + ret = alternative_call(ucode_ops.apply_microcode, patch, flags); if ( !ret ) atomic_inc(&cpu_updated); atomic_inc(&cpu_out); @@ -544,17 +556,19 @@ static int control_thread_fn(const struct microcode_patch *patch) set_nmi_callback(saved_nmi_callback); smp_wmb(); - nmi_patch = ZERO_BLOCK_PTR; + nmi_patch_with_flags.patch = ZERO_BLOCK_PTR; + nmi_patch_with_flags.flags = 0; watchdog_enable(); return ret; } -static int cf_check do_microcode_update(void *patch) +static int cf_check do_microcode_update(void *_patch_with_flags) { unsigned int cpu = smp_processor_id(); int ret; + struct patch_with_flags *patch_with_flags = _patch_with_flags; /* * The control thread set state to coordinate ucode loading. Primary @@ -562,9 +576,11 @@ static int cf_check do_microcode_update(void *patch) * the completion of the ucode loading process. */ if ( cpu == cpumask_first(&cpu_online_map) ) - ret = control_thread_fn(patch); + ret = control_thread_fn(patch_with_flags->patch, + patch_with_flags->flags); else if ( is_cpu_primary(cpu) ) - ret = primary_thread_fn(patch); + ret = primary_thread_fn(patch_with_flags->patch, + patch_with_flags->flags); else ret = secondary_thread_fn(); @@ -582,7 +598,8 @@ static long cf_check microcode_update_helper(void *data) int ret; struct ucode_buf *buffer = data; unsigned int cpu, updated; - struct microcode_patch *patch; + struct patch_with_flags patch_with_flags; + bool ucode_force = buffer->flags & XENPF_UCODE_FORCE; /* cpu_online_map must not change during update */ if ( !get_cpu_maps() ) @@ -606,16 +623,17 @@ static long cf_check microcode_update_helper(void *data) goto put; } - patch = parse_blob(buffer->buffer, buffer->len); + patch_with_flags.patch = parse_blob(buffer->buffer, buffer->len); + patch_with_flags.flags = buffer->flags; xfree(buffer); - if ( IS_ERR(patch) ) + if ( IS_ERR(patch_with_flags.patch) ) { - ret = PTR_ERR(patch); + ret = PTR_ERR(patch_with_flags.patch); printk(XENLOG_WARNING "Parsing microcode blob error %d\n", ret); goto put; } - if ( !patch ) + if ( !patch_with_flags.patch ) { printk(XENLOG_WARNING "microcode: couldn't find any matching ucode in " "the provided blob!\n"); @@ -632,17 +650,17 @@ static long cf_check microcode_update_helper(void *data) { enum microcode_match_result result; - result = alternative_call(ucode_ops.compare_patch, patch, - microcode_cache); + result = alternative_call(ucode_ops.compare_patch, + patch_with_flags.patch, microcode_cache); if ( result != NEW_UCODE && - !(opt_ucode_allow_same && result == SAME_UCODE) ) + !(ucode_force && (result == OLD_UCODE || result == SAME_UCODE)) ) { spin_unlock(µcode_mutex); printk(XENLOG_WARNING "microcode: couldn't find any newer%s revision in the provided blob!\n", - opt_ucode_allow_same ? " (or the same)" : ""); - microcode_free_patch(patch); + ucode_force? " (or a valid)" : ""); + microcode_free_patch(patch_with_flags.patch); ret = -EEXIST; goto put; @@ -674,13 +692,13 @@ static long cf_check microcode_update_helper(void *data) * this requirement can be relaxed in the future. Right now, this is * conservative and good. */ - ret = stop_machine_run(do_microcode_update, patch, NR_CPUS); + ret = stop_machine_run(do_microcode_update, &patch_with_flags, NR_CPUS); updated = atomic_read(&cpu_updated); if ( updated > 0 ) { spin_lock(µcode_mutex); - microcode_update_cache(patch); + microcode_update_cache(patch_with_flags.patch); spin_unlock(µcode_mutex); /* @@ -697,7 +715,7 @@ static long cf_check microcode_update_helper(void *data) alternative_vcall(ctxt_switch_masking, current); } else - microcode_free_patch(patch); + microcode_free_patch(patch_with_flags.patch); if ( updated && updated != nr_cores ) printk(XENLOG_ERR "ERROR: Updating microcode succeeded on %u cores and failed\n" @@ -775,7 +793,7 @@ int microcode_update_one(void) if ( !ucode_ops.apply_microcode ) return -EOPNOTSUPP; - return microcode_update_cpu(NULL); + return microcode_update_cpu(NULL, 0); } static int __init early_update_cache(const void *data, size_t len) @@ -858,7 +876,7 @@ static int __init early_microcode_update_cpu(void) if ( !patch ) return -ENOENT; - return microcode_update_cpu(patch); + return microcode_update_cpu(patch, 0); } int __init early_microcode_init(unsigned long *module_map, diff --git a/xen/arch/x86/cpu/microcode/intel.c b/xen/arch/x86/cpu/microcode/intel.c index f505aa1b7888..fc80f17d2376 100644 --- a/xen/arch/x86/cpu/microcode/intel.c +++ b/xen/arch/x86/cpu/microcode/intel.c @@ -29,6 +29,8 @@ #include "private.h" +#include "public/platform.h" + #define pr_debug(x...) ((void)0) struct microcode_patch { @@ -284,21 +286,22 @@ static enum microcode_match_result cf_check compare_patch( return compare_revisions(old->rev, new->rev); } -static int cf_check apply_microcode(const struct microcode_patch *patch) +static int cf_check apply_microcode(const struct microcode_patch *patch, + unsigned int flags) { uint64_t msr_content; unsigned int cpu = smp_processor_id(); struct cpu_signature *sig = &this_cpu(cpu_sig); uint32_t rev, old_rev = sig->rev; enum microcode_match_result result; + bool ucode_force = flags & XENPF_UCODE_FORCE; result = microcode_update_match(patch); if ( result == MIS_UCODE ) return -EINVAL; - if ( result == OLD_UCODE || - (result == SAME_UCODE && !opt_ucode_allow_same) ) + if ( !ucode_force && (result == SAME_UCODE || result == OLD_UCODE) ) return -EEXIST; wbinvd(); diff --git a/xen/arch/x86/cpu/microcode/private.h b/xen/arch/x86/cpu/microcode/private.h index da556fe5060a..017889e1b58d 100644 --- a/xen/arch/x86/cpu/microcode/private.h +++ b/xen/arch/x86/cpu/microcode/private.h @@ -3,8 +3,6 @@ #include -extern bool opt_ucode_allow_same; - enum microcode_match_result { OLD_UCODE, /* signature matched, but revision id is older */ SAME_UCODE, /* signature matched, but revision id is the same */ @@ -50,7 +48,8 @@ struct microcode_ops { * Attempt to load the provided patch into the CPU. Returns an error if * anything didn't go as expected. */ - int (*apply_microcode)(const struct microcode_patch *patch); + int (*apply_microcode)(const struct microcode_patch *patch, + unsigned int flags); /* * Given two patches, are they both applicable to the current CPU, and is