On 7/29/2021 7:44 AM, Sean Christopherson wrote:
On Fri, Jul 16, 2021, Zeng Guang wrote:
From: Robert Hoo <robert.hu@xxxxxxxxxxxxxxx>
New VMX capability MSR IA32_VMX_PROCBASED_CTLS3 conresponse to this new
VM-Execution control field. And it is 64bit allow-1 semantics, not like
previous capability MSRs 32bit allow-0 and 32bit allow-1. So with Tertiary
VM-Execution control field introduced, 2 vmx_feature leaves are introduced,
TERTIARY_CTLS_LOW and TERTIARY_CTLS_HIGH.
...
/*
* Note: If the comment begins with a quoted string, that string is used
@@ -43,6 +43,7 @@
#define VMX_FEATURE_RDTSC_EXITING ( 1*32+ 12) /* "" VM-Exit on RDTSC */
#define VMX_FEATURE_CR3_LOAD_EXITING ( 1*32+ 15) /* "" VM-Exit on writes to CR3 */
#define VMX_FEATURE_CR3_STORE_EXITING ( 1*32+ 16) /* "" VM-Exit on reads from CR3 */
+#define VMX_FEATURE_TER_CONTROLS (1*32 + 17) /* "" Enable Tertiary VM-Execution Controls */
Maybe spell out TERTIARY? SEC_CONTROLS is at least somewhat guessable, I doubt
TERTIARY is the first thing that comes to mind for most people when seeing "TER" :-)
Agree. TERTIARY could be readable without any confusion.
#define VMX_FEATURE_CR8_LOAD_EXITING ( 1*32+ 19) /* "" VM-Exit on writes to CR8 */
#define VMX_FEATURE_CR8_STORE_EXITING ( 1*32+ 20) /* "" VM-Exit on reads from CR8 */
#define VMX_FEATURE_VIRTUAL_TPR ( 1*32+ 21) /* "vtpr" TPR virtualization, a.k.a. TPR shadow */
diff --git a/arch/x86/kernel/cpu/feat_ctl.c b/arch/x86/kernel/cpu/feat_ctl.c
index da696eb4821a..2e0272d127e4 100644
--- a/arch/x86/kernel/cpu/feat_ctl.c
+++ b/arch/x86/kernel/cpu/feat_ctl.c
@@ -15,6 +15,8 @@ enum vmx_feature_leafs {
MISC_FEATURES = 0,
PRIMARY_CTLS,
SECONDARY_CTLS,
+ TERTIARY_CTLS_LOW,
+ TERTIARY_CTLS_HIGH,
NR_VMX_FEATURE_WORDS,
};
@@ -42,6 +44,13 @@ static void init_vmx_capabilities(struct cpuinfo_x86 *c)
rdmsr_safe(MSR_IA32_VMX_PROCBASED_CTLS2, &ign, &supported);
c->vmx_capability[SECONDARY_CTLS] = supported;
+ /*
+ * For tertiary execution controls MSR, it's actually a 64bit allowed-1.
+ */
+ rdmsr_safe(MSR_IA32_VMX_PROCBASED_CTLS3, &ign, &supported);
+ c->vmx_capability[TERTIARY_CTLS_LOW] = ign;
+ c->vmx_capability[TERTIARY_CTLS_HIGH] = supported;
Assuming only the lower 32 bits are going to be used for the near future (next
few years), what about defining just TERTIARY_CTLS_LOW and then doing:
/*
* Tertiary controls are 64-bit allowed-1, so unlikely other MSRs, the
* upper bits are ignored (because they're not used, yet...).
*/
rdmsr_safe(MSR_IA32_VMX_PROCBASED_CTLS3, &supported, &ign);
c->vmx_capability[TERTIARY_CTLS_LOW] = supported;
I.e. punt the ugliness issue down the road a few years.
Prefer to keep it complete, and use new variables like low/high
consistent with its function meaning. Ok for that ?
+
rdmsr(MSR_IA32_VMX_PINBASED_CTLS, ign, supported);
rdmsr_safe(MSR_IA32_VMX_VMFUNC, &ign, &funcs);
--
2.25.1
