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add reporting of SVM flags to /proc/cpuinfo

PATCH In review Joerg Roedel 4 participants 8 messages Mar 5, 2007 – Mar 6, 2007

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Joerg Roedel

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#0 lore raw

cover add reporting of SVM flags to /proc/cpuinfo

This small patch series introduces the reporting of the SVM revision, the number of ASIDs and the flags in /proc/cpuinfo on SVM capable AMD processors. The patches are for i386 and for x86_64 architectures.

Signature · 3 lines
Joerg Roedel
Operating System Research Center
AMD Saxony LLC & Co. KG
author
#1 lore raw

PATCH 1/2 x86_64: add reporting of SVM flags to /proc/cpuinfo

From: Joerg Roedel <[email protected]>

This patch adds the advanced SVM reporting to /proc/cpuinfo on the x86_64 architecture.

Signed-off-by Joerg Roedel <[email protected]>
Signature · 3 lines
Joerg Roedel
Operating System Research Center
AMD Saxony LLC & Co. KG
arch/x86_64/kernel/setup.c +31 -1
index 3d98b69..4bd06a6 100644
@@ -612,6 +612,13 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
 
 	/* RDTSC can be speculated around */
 	clear_bit(X86_FEATURE_SYNC_RDTSC, &c->x86_capability);
+
+	/* SVM specific flags and information */
+	if (cpu_has(c, X86_FEATURE_SVM)) {
+		c->svm.svm_rev = (__u8)(cpuid_eax(0x8000000a) & 0xff);
+		c->svm.svm_asids = cpuid_ebx(0x8000000a);
+		c->svm.svm_flags = cpuid_edx(0x8000000a);
+	}
 }
 
 static void __cpuinit detect_ht(struct cpuinfo_x86 *c)

@@ -992,6 +999,11 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 		/* nothing */	/* constant_tsc - moved to flags */
 	};
 
+	static char *x86_svm_flags[] = {
+		"npt",
+		"lbrv",
+		"svmlock",
+	};
 
 #ifdef CONFIG_SMP
 	if (!cpu_online(c-cpu_data))

@@ -1076,9 +1088,27 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 				else
 					seq_printf(m, " [%d]", i);
 			}
+		seq_printf(m, "\n");
+	}
+
+	if (cpu_has(c, X86_FEATURE_SVM)) {
+		unsigned i, first=1;
+		seq_printf(m, "SVM features\t: rev=%hd #asids=%u flags=(",
+				c->svm.svm_rev, c->svm.svm_asids);
+		for (i=0;i<ARRAY_SIZE(x86_svm_flags);++i) {
+			if (c->svm.svm_flags & (1 << i)) {
+				seq_printf(m,"%s", first ? "" : " ");
+				first = 0;
+				if (x86_svm_flags[i])
+					seq_printf(m, "%s", x86_svm_flags[i]);
+				else
+					seq_printf(m, "[%d]", i);
+			}
+		}
+		seq_printf(m, ")\n");
 	}
 
-	seq_printf(m, "\n\n");
+	seq_printf(m, "\n");
 
 	return 0;
 }
include/asm-x86_64/cpufeature.h +1 -0
index 0b3c686..869d8a5 100644
@@ -90,6 +90,7 @@
 /* More extended AMD flags: CPUID level 0x80000001, ecx, word 6 */
 #define X86_FEATURE_LAHF_LM	(6*32+ 0) /* LAHF/SAHF in long mode */
 #define X86_FEATURE_CMP_LEGACY	(6*32+ 1) /* If yes HyperThreading not valid */
+#define X86_FEATURE_SVM         (6*32+ 2) /* Secure Virtual Machine */
 
 #define cpu_has(c, bit)                test_bit(bit, (c)->x86_capability)
 #define boot_cpu_has(bit)      test_bit(bit, boot_cpu_data.x86_capability)
include/asm-x86_64/processor.h +11 -0
index 76552d7..514520b 100644
@@ -43,6 +43,15 @@
  */
 #define current_text_addr() ({ void *pc; asm volatile("leaq 1f(%%rip),%0\n1:":"=r"(pc)); pc; })
 
+ /*
+  * SVM flags subtype - used in struct cpuinfo_x86
+  */
+struct cpu_svm_info {
+	__u8 svm_rev;
+	__u32 svm_asids;
+	__u32 svm_flags;
+};
+
 /*
  *  CPU type and hardware bug flags. Kept separately for each CPU.
  */

@@ -73,6 +82,8 @@ struct cpuinfo_x86 {
 	__u8	booted_cores;	/* number of cores as seen by OS */
 	__u8	phys_proc_id;	/* Physical Processor id. */
 	__u8	cpu_core_id;	/* Core id. */
+
+	struct cpu_svm_info svm; /* SVM specific feature flags */
 #endif
 } ____cacheline_aligned;
#2 lore raw

Re: [PATCH 1/2] x86_64: add reporting of SVM flags to /proc/cpuinfo

arch/x86_64/kernel/setup.c static int show_cpuinfo(struct seq_file *m, void *v) · line 1006

Quoted 6 lines · Joerg Roedel

+++ b/arch/x86_64/kernel/setup.c

arch/x86_64/kernel/setup.c +5 -0
+	static char *x86_svm_flags[] = {
+		"npt",
+		"lbrv",
+		"svmlock",
+	};

A nitpick:

static const char *const x86_svm_flags[] = ... ?

/mjt

author
#3 lore raw

Re: [PATCH 1/2] x86_64: add reporting of SVM flags to /proc/cpuinfo

Quoted 11 lines · Michael Tokarev

arch/x86_64/kernel/setup.c static int show_cpuinfo(struct seq_file *m, void *v) · line 1006

Quoted 6 lines · Joerg Roedel

+++ b/arch/x86_64/kernel/setup.c

arch/x86_64/kernel/setup.c +5 -0
+	static char *x86_svm_flags[] = {
+		"npt",
+		"lbrv",
+		"svmlock",
+	};

A nitpick:

static const char *const x86_svm_flags[] = ... ?

Right. Its better to mark the array as const. Will wait for more comments and send an updated patch soon.

Thanks,
Joerg

Signature · 3 lines
Joerg Roedel
Operating System Research Center
AMD Saxony LLC & Co. KG
#4 lore raw

Re: [PATCH 1/2] x86_64: add reporting of SVM flags to /proc/cpuinfo

In reply to Joerg Roedel
Quoted 4 lines · Joerg Roedel

From: Joerg Roedel <[email protected]>

This patch adds the advanced SVM reporting to /proc/cpuinfo on the x86_64 architecture.

Adding more fields to /proc/cpuinfo is always somewhat risky because there are lots of badly written parsers for it.

I considered adding the SVM fields myself, but decided against it because it didn't seem generally useful enough.

-Andi

#5 lore raw

Re: [discuss] [PATCH 1/2] x86_64: add reporting of SVM flags to /proc/cpuinfo

Quoted 11 lines · Andi Kleen
Quoted 4 lines · Joerg Roedel

From: Joerg Roedel <[email protected]>

This patch adds the advanced SVM reporting to /proc/cpuinfo on the x86_64 architecture.

Adding more fields to /proc/cpuinfo is always somewhat risky because there are lots of badly written parsers for it.

I considered adding the SVM fields myself, but decided against it because it didn't seem generally useful enough.

Agreed. I'm more than happy to take patches to x86info however :)

Dave

Signature · 1 line
http://www.codemonkey.org.uk
author
#6 lore raw

Re: [PATCH 1/2] x86_64: add reporting of SVM flags to /proc/cpuinfo

In reply to Andi Kleen
Quoted 8 lines · Andi Kleen
Quoted 4 lines · Joerg Roedel

From: Joerg Roedel <[email protected]>

This patch adds the advanced SVM reporting to /proc/cpuinfo on the x86_64 architecture.

Adding more fields to /proc/cpuinfo is always somewhat risky because there are lots of badly written parsers for it.

Can you point me to some really broken parsers of /proc/cpuinfo to test with?

Quoted 2 lines

I considered adding the SVM fields myself, but decided against it because it didn't seem generally useful enough.

I don't see that this is less important than the power flags in that file. Some users might be interested to see if their processor has npt for example by simply looking into cpuinfo.
As I said, would be interested to know more about these badly written parsers.

Joerg

Signature · 3 lines
Joerg Roedel
Operating System Research Center
AMD Saxony LLC & Co. KG
author
#7 lore raw

PATCH 2/2 i386: add reporting of SVM flags to /proc/cpuinfo

In reply to Joerg Roedel

From: Joerg Roedel <[email protected]>

This patch adds the advanced SVM reporting in /proc/cpuinfo to the i386 architecture.

Signed-off-by Joerg Roedel <[email protected]>
Signature · 3 lines
Joerg Roedel
Operating System Research Center
AMD Saxony LLC & Co. KG
arch/i386/kernel/cpu/amd.c +7 -0
index 41cfea5..768c221 100644
@@ -241,6 +241,13 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
 
 	if (cpuid_eax(0x80000000) >= 0x80000006)
 		num_cache_leaves = 3;
+
+	/* SVM specific flags and information */
+	if (cpu_has(c, X86_FEATURE_SVM)) {
+		c->svm.svm_rev = (__u8)(cpuid_eax(0x8000000a) & 0xff);
+		c->svm.svm_asids = cpuid_ebx(0x8000000a);
+		c->svm.svm_flags = cpuid_edx(0x8000000a);
+	}
 }
 
 static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 * c, unsigned int size)
arch/i386/kernel/cpu/proc.c +26 -1
index 47e3ebb..ddedf56 100644
@@ -76,6 +76,13 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 		NULL,	/* constant_tsc - moved to flags */
 		/* nothing */
 	};
+
+	static char *x86_svm_flags[] = {
+		"npt",
+		"lbrv",
+		"svmlock",
+	};
+
 	struct cpuinfo_x86 *c = v;
 	int i, n = c - cpu_data;
 	int fpu_exception;

@@ -159,7 +166,25 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 	seq_printf(m, "\nbogomips\t: %lu.%02lu\n",
 		     c->loops_per_jiffy/(500000/HZ),
 		     (c->loops_per_jiffy/(5000/HZ)) % 100);
-	seq_printf(m, "clflush size\t: %u\n\n", c->x86_clflush_size);
+	seq_printf(m, "clflush size\t: %u\n", c->x86_clflush_size);
+
+	if (cpu_has(c, X86_FEATURE_SVM)) {
+		unsigned i, first=1;
+		seq_printf(m, "SVM features\t: rev=%hd #asids=%u flags=(",
+				c->svm.svm_rev, c->svm.svm_asids);
+		for (i=0;i<ARRAY_SIZE(x86_svm_flags);++i) {
+			if (c->svm.svm_flags & (1 << i)) {
+				seq_printf(m,"%s", first ? "" : " ");
+				first = 0;
+				if (x86_svm_flags[i])
+					seq_printf(m, "%s", x86_svm_flags[i]);
+				else
+					seq_printf(m, "[%d]", i);
+			}
+		}
+		seq_printf(m, ")\n");
+	}
+	seq_printf(m, "\n");
 
 	return 0;
 }
include/asm-i386/cpufeature.h +1 -0
index 3f92b94..4da2dba 100644
@@ -101,6 +101,7 @@
 /* More extended AMD flags: CPUID level 0x80000001, ecx, word 6 */
 #define X86_FEATURE_LAHF_LM	(6*32+ 0) /* LAHF/SAHF in long mode */
 #define X86_FEATURE_CMP_LEGACY	(6*32+ 1) /* If yes HyperThreading not valid */
+#define X86_FEATURE_SVM         (6*32+ 2) /* Secure Virtual Machine */
 
 #define cpu_has(c, bit)		test_bit(bit, (c)->x86_capability)
 #define boot_cpu_has(bit)	test_bit(bit, boot_cpu_data.x86_capability)
include/asm-i386/processor.h +10 -0
index 11bf899..727c54f 100644
@@ -41,6 +41,15 @@ struct desc_struct {
 #define current_text_addr() ({ void *pc; __asm__("movl $1f,%0\n1:":"=g" (pc)); pc; })
 
 /*
+ * SVM flags subtype - used in struct cpuinfo_x86
+ */
+struct cpu_svm_info {
+	__u8 svm_rev;
+	__u32 svm_asids;
+	__u32 svm_flags;
+};
+
+/*
  *  CPU type and hardware bug flags. Kept separately for each CPU.
  *  Members of this structure are referenced in head.S, so think twice
  *  before touching them. [mj]

@@ -79,6 +88,7 @@ struct cpuinfo_x86 {
 	__u8 phys_proc_id; 		/* Physical processor id. */
 	__u8 cpu_core_id;  		/* Core id */
 #endif
+	struct cpu_svm_info svm;
 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
 
 #define X86_VENDOR_INTEL 0