linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Andi Kleen <andi@firstfloor.org>
To: peterz@infradead.org
Cc: x86@kernel.org, eranian@google.com, kan.liang@intel.com,
	linux-kernel@vger.kernel.org, Andi Kleen <ak@linux.intel.com>
Subject: [PATCH v2 1/2] x86/cpufeature: Add facility to match microcode revisions
Date: Wed, 10 Oct 2018 09:26:07 -0700	[thread overview]
Message-ID: <20181010162608.23899-1-andi@firstfloor.org> (raw)

From: Andi Kleen <ak@linux.intel.com>

For bug workarounds or checks it is useful to check for specific
microcode versions. Add a new table format to check for steppings
with min microcode revisions.

This does not change the existing x86_cpu_id because it's an ABI
shared with modutils, and also has quite difference requirements,
as in no wildcards, but everything has to be matched exactly.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
v2:
Remove all CPU match, only check boot cpu
Move INTEL_MIN_UCODE macro to header.
Minor cleanups.
Remove max ucode and driver data
---
 arch/x86/include/asm/cpu_device_id.h | 26 ++++++++++++++++++++++++++
 arch/x86/kernel/cpu/match.c          | 21 +++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/arch/x86/include/asm/cpu_device_id.h b/arch/x86/include/asm/cpu_device_id.h
index baeba0567126..1b90bd1d0b95 100644
--- a/arch/x86/include/asm/cpu_device_id.h
+++ b/arch/x86/include/asm/cpu_device_id.h
@@ -11,4 +11,30 @@
 
 extern const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match);
 
+/*
+ * Match specific microcodes
+ *
+ * vendor/family/model/stepping must be all set.
+ * min_ucode is optional and can be 0.
+ */
+
+struct x86_ucode_id {
+	u8 vendor;
+	u8 family;
+	u16 model;
+	u16 stepping;
+	u32 min_ucode;
+};
+
+#define INTEL_MIN_UCODE(mod, step, rev) {			\
+	.vendor = X86_VENDOR_INTEL,				\
+	.family = 6,						\
+	.model = mod,						\
+	.stepping = step,					\
+	.min_ucode = rev,					\
+}
+
+extern const struct x86_ucode_id *
+x86_match_ucode(const struct x86_ucode_id *match);
+
 #endif
diff --git a/arch/x86/kernel/cpu/match.c b/arch/x86/kernel/cpu/match.c
index 3fed38812eea..ec8ee31699cd 100644
--- a/arch/x86/kernel/cpu/match.c
+++ b/arch/x86/kernel/cpu/match.c
@@ -48,3 +48,24 @@ const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match)
 	return NULL;
 }
 EXPORT_SYMBOL(x86_match_cpu);
+
+const struct x86_ucode_id *x86_match_ucode(const struct x86_ucode_id *match)
+{
+	struct cpuinfo_x86 *c = &boot_cpu_data;
+	const struct x86_ucode_id *m;
+
+	for (m = match; m->vendor | m->family | m->model; m++) {
+		if (c->x86_vendor != m->vendor)
+			continue;
+		if (c->x86 != m->family)
+			continue;
+		if (c->x86_model != m->model)
+			continue;
+		if (c->x86_stepping != m->stepping)
+			continue;
+		if (c->microcode < m->min_ucode)
+			continue;
+		return m;
+	}
+	return NULL;
+}
-- 
2.17.1


             reply	other threads:[~2018-10-10 16:26 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-10 16:26 Andi Kleen [this message]
2018-10-10 16:26 ` [PATCH v2 2/2] perf/x86/kvm: Avoid unnecessary work in guest filtering Andi Kleen
2018-10-10 16:37 ` [PATCH v2 1/2] x86/cpufeature: Add facility to match microcode revisions Borislav Petkov
2018-10-11 11:43 ` Henrique de Moraes Holschuh
2018-10-17  9:59 ` Thomas Gleixner
2018-10-19 23:47   ` Andi Kleen
2018-10-20  8:19     ` Thomas Gleixner
2018-10-20 14:38       ` Andi Kleen
2018-10-21 10:20         ` Thomas Gleixner
2018-10-21 15:13           ` Borislav Petkov
2018-10-25 23:23           ` Andi Kleen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20181010162608.23899-1-andi@firstfloor.org \
    --to=andi@firstfloor.org \
    --cc=ak@linux.intel.com \
    --cc=eranian@google.com \
    --cc=kan.liang@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=peterz@infradead.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).