lkml.org 
[lkml]   [2023]   [May]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v2 3/3] x86/cpu, KVM: Use helper function to read MSR_IA32_ARCH_CAPABILITIES
From
On 5/24/2023 2:16 PM, Chao Gao wrote:
> KVM open-codes x86_read_arch_cap_msr() in a few places. Eliminate them
> by exposing the helper function and using it directly.
>
> No functional change intended.
>

Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>

> Signed-off-by: Chao Gao <chao.gao@intel.com>
> ---
> arch/x86/kernel/cpu/common.c | 1 +
> arch/x86/kvm/vmx/vmx.c | 19 +++++--------------
> arch/x86/kvm/x86.c | 7 +------
> 3 files changed, 7 insertions(+), 20 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
> index 80710a68ef7d..b34dd3f3e6c4 100644
> --- a/arch/x86/kernel/cpu/common.c
> +++ b/arch/x86/kernel/cpu/common.c
> @@ -1315,6 +1315,7 @@ u64 x86_read_arch_cap_msr(void)
>
> return ia32_cap;
> }
> +EXPORT_SYMBOL_GPL(x86_read_arch_cap_msr);
>
> static bool arch_cap_mmio_immune(u64 ia32_cap)
> {
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 8274ef5e89e5..3dec4a4f637e 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -255,14 +255,9 @@ static int vmx_setup_l1d_flush(enum vmx_l1d_flush_state l1tf)
> return 0;
> }
>
> - if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES)) {
> - u64 msr;
> -
> - rdmsrl(MSR_IA32_ARCH_CAPABILITIES, msr);
> - if (msr & ARCH_CAP_SKIP_VMENTRY_L1DFLUSH) {
> - l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_NOT_REQUIRED;
> - return 0;
> - }
> + if (x86_read_arch_cap_msr() & ARCH_CAP_SKIP_VMENTRY_L1DFLUSH) {
> + l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_NOT_REQUIRED;
> + return 0;
> }
>
> /* If set to auto use the default l1tf mitigation method */
> @@ -394,13 +389,9 @@ static int vmentry_l1d_flush_get(char *s, const struct kernel_param *kp)
>
> static void vmx_setup_fb_clear_ctrl(void)
> {
> - u64 msr;
> -
> - if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES) &&
> - !boot_cpu_has_bug(X86_BUG_MDS) &&
> + if (!boot_cpu_has_bug(X86_BUG_MDS) &&
> !boot_cpu_has_bug(X86_BUG_TAA)) {
> - rdmsrl(MSR_IA32_ARCH_CAPABILITIES, msr);
> - if (msr & ARCH_CAP_FB_CLEAR_CTRL)
> + if (x86_read_arch_cap_msr() & ARCH_CAP_FB_CLEAR_CTRL)
> vmx_fb_clear_ctrl_available = true;
> }
> }
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index f7838260c183..b1bdb84ac10f 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1612,12 +1612,7 @@ static bool kvm_is_immutable_feature_msr(u32 msr)
>
> static u64 kvm_get_arch_capabilities(void)
> {
> - u64 data = 0;
> -
> - if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES)) {
> - rdmsrl(MSR_IA32_ARCH_CAPABILITIES, data);
> - data &= KVM_SUPPORTED_ARCH_CAP;
> - }
> + u64 data = x86_read_arch_cap_msr() & KVM_SUPPORTED_ARCH_CAP;
>
> /*
> * If nx_huge_pages is enabled, KVM's shadow paging will ensure that

\
 
 \ /
  Last update: 2023-05-24 10:21    [W:0.158 / U:0.316 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site