[PATCH v3 14/19] x86/cpu: Print VMX flags in /proc/cpuinfo using VMX_FEATURES_*

Sean Christopherson
2019-11-19T03:13:50Z

Add support for generating VMX feature names in capflags.c and use the
resulting x86_vmx_flags to print the VMX flags in /proc/cpuinfo. Remove
all code which sets the synthetic VMX flags in cpufeatures so that
"flags" doesn't contain duplicate VMX features. The synthetic flags
themselves will be removed shortly.

Do not print VMX flags if no bits are set in word 0, which includes Pin
Controls. INTR and NMI exiting are fundamental pillars of VMX, if they
are not supported then the CPU is broken, it does not actually support
VMX, or the kernel wasn't built with support for the target CPU.

Note, ideally VMX flags would be a separate line in /proc/cpuinfo, e.g.
as "vmx_flags", but doing so would break the ABI with respect to the
existing synthetic VMX flags in cpufeatures.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/boot/mkcpustr.c | 1 +
arch/x86/kernel/cpu/Makefile | 5 ++--
arch/x86/kernel/cpu/centaur.c | 35 ----------------------
arch/x86/kernel/cpu/intel.c | 49 -------------------------------
arch/x86/kernel/cpu/mkcapflags.sh | 15 +++++++---
arch/x86/kernel/cpu/proc.c | 14 +++++++++
arch/x86/kernel/cpu/zhaoxin.c | 35 ----------------------
7 files changed, 29 insertions(+), 125 deletions(-)

diff --git a/arch/x86/boot/mkcpustr.c b/arch/x86/boot/mkcpustr.c
index 9caa10e82217..da0ccc5de538 100644
--- a/arch/x86/boot/mkcpustr.c
+++ b/arch/x86/boot/mkcpustr.c
@@ -15,6 +15,7 @@
#include "../include/asm/required-features.h"
#include "../include/asm/disabled-features.h"
#include "../include/asm/cpufeatures.h"
+#include "../include/asm/vmxfeatures.h"
#include "../kernel/cpu/capflags.c"

int main(void)
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 84e35e762f76..fae9448678f3 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -54,11 +54,12 @@ obj-$(CONFIG_ACRN_GUEST) += acrn.o

ifdef CONFIG_X86_FEATURE_NAMES
quiet_cmd_mkcapflags = MKCAP $@
- cmd_mkcapflags = $(CONFIG_SHELL) $(srctree)/$(src)/mkcapflags.sh $< $@
+ cmd_mkcapflags = $(CONFIG_SHELL) $(srctree)/$(src)/mkcapflags.sh $@ $^

cpufeature = $(src)/../../include/asm/cpufeatures.h
+vmxfeature = $(src)/../../include/asm/vmxfeatures.h

-$(obj)/capflags.c: $(cpufeature) $(src)/mkcapflags.sh FORCE
+$(obj)/capflags.c: $(cpufeature) $(vmxfeature) $(src)/mkcapflags.sh FORCE
$(call if_changed,mkcapflags)
endif
targets += capflags.c
diff --git a/arch/x86/kernel/cpu/centaur.c b/arch/x86/kernel/cpu/centaur.c
index a6ca4c31c1b6..be11c796926b 100644
--- a/arch/x86/kernel/cpu/centaur.c
+++ b/arch/x86/kernel/cpu/centaur.c
@@ -18,13 +18,6 @@
#define RNG_ENABLED (1 << 3)
#define RNG_ENABLE (1 << 6) /* MSR_VIA_RNG */

-#define X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW 0x00200000
-#define X86_VMX_FEATURE_PROC_CTLS_VNMI 0x00400000
-#define X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS 0x80000000
-#define X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC 0x00000001
-#define X86_VMX_FEATURE_PROC_CTLS2_EPT 0x00000002
-#define X86_VMX_FEATURE_PROC_CTLS2_VPID 0x00000020
-
static void init_c3(struct cpuinfo_x86 *c)
{
u32 lo, hi;
@@ -119,31 +112,6 @@ static void early_init_centaur(struct cpuinfo_x86 *c)
}
}

-static void centaur_detect_vmx_virtcap(struct cpuinfo_x86 *c)
-{
- u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;
-
- rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low, vmx_msr_high);
- msr_ctl = vmx_msr_high | vmx_msr_low;
-
- if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
- set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
- if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
- set_cpu_cap(c, X86_FEATURE_VNMI);
- if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS) {
- rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
- vmx_msr_low, vmx_msr_high);
- msr_ctl2 = vmx_msr_high | vmx_msr_low;
- if ((msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC) &&
- (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW))
- set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
- if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT)
- set_cpu_cap(c, X86_FEATURE_EPT);
- if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
- set_cpu_cap(c, X86_FEATURE_VPID);
- }
-}
-
static void init_centaur(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_X86_32
@@ -251,9 +219,6 @@ static void init_centaur(struct cpuinfo_x86 *c)
#endif

init_feature_control_msr(c);
-
- if (cpu_has(c, X86_FEATURE_VMX))
- centaur_detect_vmx_virtcap(c);
}

#ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index b7c6ed0b40b6..3d4b3fc6bd4b 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -494,52 +494,6 @@ static void srat_detect_node(struct cpuinfo_x86 *c)
#endif
}

-static void detect_vmx_virtcap(struct cpuinfo_x86 *c)
-{
- /* Intel VMX MSR indicated features */
-#define X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW 0x00200000
-#define X86_VMX_FEATURE_PROC_CTLS_VNMI 0x00400000
-#define X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS 0x80000000
-#define X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC 0x00000001
-#define X86_VMX_FEATURE_PROC_CTLS2_EPT 0x00000002
-#define X86_VMX_FEATURE_PROC_CTLS2_VPID 0x00000020
-#define x86_VMX_FEATURE_EPT_CAP_AD 0x00200000
-
- u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;
- u32 msr_vpid_cap, msr_ept_cap;
-
- clear_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
- clear_cpu_cap(c, X86_FEATURE_VNMI);
- clear_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
- clear_cpu_cap(c, X86_FEATURE_EPT);
- clear_cpu_cap(c, X86_FEATURE_VPID);
- clear_cpu_cap(c, X86_FEATURE_EPT_AD);
-
- rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low, vmx_msr_high);
- msr_ctl = vmx_msr_high | vmx_msr_low;
- if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
- set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
- if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
- set_cpu_cap(c, X86_FEATURE_VNMI);
- if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS) {
- rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
- vmx_msr_low, vmx_msr_high);
- msr_ctl2 = vmx_msr_high | vmx_msr_low;
- if ((msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC) &&
- (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW))
- set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
- if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT) {
- set_cpu_cap(c, X86_FEATURE_EPT);
- rdmsr(MSR_IA32_VMX_EPT_VPID_CAP,
- msr_ept_cap, msr_vpid_cap);
- if (msr_ept_cap & x86_VMX_FEATURE_EPT_CAP_AD)
- set_cpu_cap(c, X86_FEATURE_EPT_AD);
- }
- if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
- set_cpu_cap(c, X86_FEATURE_VPID);
- }
-}
-
#define MSR_IA32_TME_ACTIVATE 0x982

/* Helpers to access TME_ACTIVATE MSR */
@@ -757,9 +711,6 @@ static void init_intel(struct cpuinfo_x86 *c)

init_feature_control_msr(c);

- if (cpu_has(c, X86_FEATURE_VMX))
- detect_vmx_virtcap(c);
-
if (cpu_has(c, X86_FEATURE_TME))
detect_tme(c);

diff --git a/arch/x86/kernel/cpu/mkcapflags.sh b/arch/x86/kernel/cpu/mkcapflags.sh
index aed45b8895d5..1db560ed2ca3 100644
--- a/arch/x86/kernel/cpu/mkcapflags.sh
+++ b/arch/x86/kernel/cpu/mkcapflags.sh
@@ -6,8 +6,7 @@

set -e

-IN=$1
-OUT=$2
+OUT=$1

dump_array()
{
@@ -15,6 +14,7 @@ dump_array()
SIZE=$2
PFX=$3
POSTFIX=$4
+ IN=$5

PFX_SZ=$(echo $PFX | wc -c)
TABS="$(printf '\t\t\t\t\t')"
@@ -57,11 +57,18 @@ trap 'rm "$OUT"' EXIT
echo "#endif"
echo ""

- dump_array "x86_cap_flags" "NCAPINTS*32" "X86_FEATURE_" ""
+ dump_array "x86_cap_flags" "NCAPINTS*32" "X86_FEATURE_" "" $2
echo ""

- dump_array "x86_bug_flags" "NBUGINTS*32" "X86_BUG_" "NCAPINTS*32"
+ dump_array "x86_bug_flags" "NBUGINTS*32" "X86_BUG_" "NCAPINTS*32" $2
+ echo ""

+ echo "#ifdef CONFIG_X86_VMX_FEATURE_NAMES"
+ echo "#ifndef _ASM_X86_VMXFEATURES_H"
+ echo "#include <asm/vmxfeatures.h>"
+ echo "#endif"
+ dump_array "x86_vmx_flags" "NVMXINTS*32" "VMX_FEATURE_" "" $3
+ echo "#endif /* CONFIG_X86_VMX_FEATURE_NAMES */"
) > $OUT

trap - EXIT
diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c
index cb2e49810d68..8f118111279a 100644
--- a/arch/x86/kernel/cpu/proc.c
+++ b/arch/x86/kernel/cpu/proc.c
@@ -7,6 +7,10 @@

#include "cpu.h"

+#ifdef CONFIG_X86_VMX_FEATURE_NAMES
+extern const char * const x86_vmx_flags[NVMXINTS*32];
+#endif
+
/*
* Get CPU information for use by the procfs.
*/
@@ -102,6 +106,16 @@ static int show_cpuinfo(struct seq_file *m, void *v)
if (cpu_has(c, i) && x86_cap_flags[i] != NULL)
seq_printf(m, " %s", x86_cap_flags[i]);

+#ifdef CONFIG_X86_VMX_FEATURE_NAMES
+ if (cpu_has(c, X86_FEATURE_VMX) && c->vmx_capability[0]) {
+ for (i = 0; i < 32*NVMXINTS; i++) {
+ if (test_bit(i, (unsigned long *)c->vmx_capability) &&
+ x86_vmx_flags[i] != NULL)
+ seq_printf(m, " %s", x86_vmx_flags[i]);
+ }
+ }
+#endif
+
seq_puts(m, "\nbugs\t\t:");
for (i = 0; i < 32*NBUGINTS; i++) {
unsigned int bug_bit = 32*NCAPINTS + i;
diff --git a/arch/x86/kernel/cpu/zhaoxin.c b/arch/x86/kernel/cpu/zhaoxin.c
index 01b05a4a5a85..edfc7cc4ec33 100644
--- a/arch/x86/kernel/cpu/zhaoxin.c
+++ b/arch/x86/kernel/cpu/zhaoxin.c
@@ -16,13 +16,6 @@
#define RNG_ENABLED (1 << 3)
#define RNG_ENABLE (1 << 8) /* MSR_ZHAOXIN_RNG */

-#define X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW 0x00200000
-#define X86_VMX_FEATURE_PROC_CTLS_VNMI 0x00400000
-#define X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS 0x80000000
-#define X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC 0x00000001
-#define X86_VMX_FEATURE_PROC_CTLS2_EPT 0x00000002
-#define X86_VMX_FEATURE_PROC_CTLS2_VPID 0x00000020
-
static void init_zhaoxin_cap(struct cpuinfo_x86 *c)
{
u32 lo, hi;
@@ -89,31 +82,6 @@ static void early_init_zhaoxin(struct cpuinfo_x86 *c)

}

-static void zhaoxin_detect_vmx_virtcap(struct cpuinfo_x86 *c)
-{
- u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;
-
- rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low, vmx_msr_high);
- msr_ctl = vmx_msr_high | vmx_msr_low;
-
- if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
- set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
- if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
- set_cpu_cap(c, X86_FEATURE_VNMI);
- if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS) {
- rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
- vmx_msr_low, vmx_msr_high);
- msr_ctl2 = vmx_msr_high | vmx_msr_low;
- if ((msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC) &&
- (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW))
- set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
- if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT)
- set_cpu_cap(c, X86_FEATURE_EPT);
- if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
- set_cpu_cap(c, X86_FEATURE_VPID);
- }
-}
-
static void init_zhaoxin(struct cpuinfo_x86 *c)
{
early_init_zhaoxin(c);
@@ -142,9 +110,6 @@ static void init_zhaoxin(struct cpuinfo_x86 *c)
#endif

init_feature_control_msr(c);
-
- if (cpu_has(c, X86_FEATURE_VMX))
- zhaoxin_detect_vmx_virtcap(c);
}

#ifdef CONFIG_X86_32
--
2.24.0