Re: [PATCH 11/16] x86/cpu: Print VMX features as separate line item in /proc/cpuinfo

From: Paolo Bonzini
Date: Mon Oct 07 2019 - 13:12:39 EST

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In reply to: Sean Christopherson: "[PATCH 11/16] x86/cpu: Print VMX features as separate line item in /proc/cpuinfo"
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On 04/10/19 23:56, Sean Christopherson wrote:
> Add support for generating VMX feature names in capflags.c and printing
> the resulting names in /proc/cpuinfo as "vmx flags" when VMX support is
> detected. 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
> virtualization, if they're 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.
>
> Remove all code which sets the synthetic VMX flags in cpufeatures so
> that duplicate VMX features are not printed in "flags" and "vmx flags".
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> ---
> 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 | 15 ++++++++++
> arch/x86/kernel/cpu/zhaoxin.c | 35 ----------------------
> 7 files changed, 30 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 df5ad0cfe3e9..025cbfd45687 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 15d59224e2f8..594d2686ad52 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..4eec8889b0ff 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 +106,17 @@ 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]);

I'm afraid this is going to break some scripts in the wild. I would
simply remove the seq_puts below.

Paolo

> +#ifdef CONFIG_X86_VMX_FEATURE_NAMES
> + if (cpu_has(c, X86_FEATURE_VMX) && c->vmx_capability[0]) {
> + seq_puts(m, "\nvmx flags\t:");
> + 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
>

Next message: David Z. Dai: "Re: [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm"
Previous message: Dan Murphy: "[PATCH] ASoc: tas2770: Remove unused defines and variables"
In reply to: Sean Christopherson: "[PATCH 11/16] x86/cpu: Print VMX features as separate line item in /proc/cpuinfo"
Next in thread: Sean Christopherson: "Re: [PATCH 11/16] x86/cpu: Print VMX features as separate line item in /proc/cpuinfo"
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