git: bf5683caedae - stable/13 - vmm vmx: Add a global bool to indicate if the host has the TSC_AUX MSR.

From: John Baldwin <jhb_at_FreeBSD.org>
Date: Thu, 26 Jan 2023 22:11:41 UTC
The branch stable/13 has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=bf5683caedae298a17dfed91aeddb8249772c136

commit bf5683caedae298a17dfed91aeddb8249772c136
Author:     John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2022-11-18 17:58:56 +0000
Commit:     John Baldwin <jhb@FreeBSD.org>
CommitDate: 2023-01-26 21:44:42 +0000

    vmm vmx: Add a global bool to indicate if the host has the TSC_AUX MSR.
    
    A future commit will remove direct access to vCPU structures from
    struct vmx, so add a dedicated boolean for this rather than checking
    the capabilities for vCPU 0.
    
    Reviewed by:    corvink, markj
    Differential Revision:  https://reviews.freebsd.org/D37269
    
    (cherry picked from commit 73abae4493782e44a3382b15f5563c3f400bf51f)
---
 sys/amd64/vmm/intel/vmx.c     |  6 +++++-
 sys/amd64/vmm/intel/vmx.h     | 16 ++--------------
 sys/amd64/vmm/intel/vmx_msr.c |  6 +++---
 3 files changed, 10 insertions(+), 18 deletions(-)

diff --git a/sys/amd64/vmm/intel/vmx.c b/sys/amd64/vmm/intel/vmx.c
index 7ece03a44952..96e7907622cf 100644
--- a/sys/amd64/vmm/intel/vmx.c
+++ b/sys/amd64/vmm/intel/vmx.c
@@ -127,6 +127,8 @@ __FBSDID("$FreeBSD$");
 static MALLOC_DEFINE(M_VMX, "vmx", "vmx");
 static MALLOC_DEFINE(M_VLAPIC, "vlapic", "vlapic");
 
+bool vmx_have_msr_tsc_aux;
+
 SYSCTL_DECL(_hw_vmm);
 SYSCTL_NODE(_hw_vmm, OID_AUTO, vmx, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
     NULL);
@@ -821,8 +823,10 @@ vmx_modinit(int ipinum)
 			       PROCBASED2_ENABLE_RDTSCP, 0, &tmp);
 	cap_rdpid = error == 0 && host_has_rdpid();
 	cap_rdtscp = error == 0 && host_has_rdtscp();
-	if (cap_rdpid || cap_rdtscp)
+	if (cap_rdpid || cap_rdtscp) {
 		procbased_ctls2 |= PROCBASED2_ENABLE_RDTSCP;
+		vmx_have_msr_tsc_aux = true;
+	}
 
 	cap_unrestricted_guest = (vmx_set_ctlreg(MSR_VMX_PROCBASED_CTLS2,
 					MSR_VMX_PROCBASED_CTLS2,
diff --git a/sys/amd64/vmm/intel/vmx.h b/sys/amd64/vmm/intel/vmx.h
index 8168b82bfe5c..39594473cd43 100644
--- a/sys/amd64/vmm/intel/vmx.h
+++ b/sys/amd64/vmm/intel/vmx.h
@@ -142,6 +142,8 @@ struct vmx {
 	long		eptgen[MAXCPU];		/* cached pmap->pm_eptgen */
 };
 
+extern bool vmx_have_msr_tsc_aux;
+
 #define	VMX_GUEST_VMEXIT	0
 #define	VMX_VMRESUME_ERROR	1
 #define	VMX_VMLAUNCH_ERROR	2
@@ -156,18 +158,4 @@ int	vmx_set_tsc_offset(struct vmx *vmx, int vcpu, uint64_t offset);
 extern char	vmx_exit_guest[];
 extern char	vmx_exit_guest_flush_rsb[];
 
-static inline bool
-vmx_have_msr_tsc_aux(struct vmx *vmx)
-{
-	int rdpid_rdtscp_bits = ((1 << VM_CAP_RDPID) | (1 << VM_CAP_RDTSCP));
-
-	/*
-	 * Since the values of these bits are uniform across all vCPUs
-	 * (see discussion in vmx_modinit() and initialization of these bits
-	 * in vmx_init()), just always use vCPU-zero's capability set and
-	 * remove the need to require a vcpuid argument.
-	 */
-	return ((vmx->vcpus[0].cap.set & rdpid_rdtscp_bits) != 0);
-}
-
 #endif
diff --git a/sys/amd64/vmm/intel/vmx_msr.c b/sys/amd64/vmm/intel/vmx_msr.c
index 0d4e86edf60c..40f0057f2cdd 100644
--- a/sys/amd64/vmm/intel/vmx_msr.c
+++ b/sys/amd64/vmm/intel/vmx_msr.c
@@ -366,7 +366,7 @@ vmx_msr_guest_enter_tsc_aux(struct vmx *vmx, int vcpuid)
 	uint64_t guest_tsc_aux = vmx_vcpu->guest_msrs[IDX_MSR_TSC_AUX];
 	uint32_t host_aux = cpu_auxmsr();
 
-	if (vmx_have_msr_tsc_aux(vmx) && guest_tsc_aux != host_aux)
+	if (vmx_have_msr_tsc_aux && guest_tsc_aux != host_aux)
 		wrmsr(MSR_TSC_AUX, guest_tsc_aux);
 }
 
@@ -398,7 +398,7 @@ vmx_msr_guest_exit_tsc_aux(struct vmx *vmx, int vcpuid)
 	uint64_t guest_tsc_aux = vmx_vcpu->guest_msrs[IDX_MSR_TSC_AUX];
 	uint32_t host_aux = cpu_auxmsr();
 
-	if (vmx_have_msr_tsc_aux(vmx) && guest_tsc_aux != host_aux)
+	if (vmx_have_msr_tsc_aux && guest_tsc_aux != host_aux)
 		/*
 		 * Note that it is not necessary to save the guest value
 		 * here; vmx->guest_msrs[vcpuid][IDX_MSR_TSC_AUX] always
@@ -505,7 +505,7 @@ vmx_wrmsr(struct vmx *vmx, int vcpuid, u_int num, uint64_t val, bool *retu)
 		error = vmx_set_tsc_offset(vmx, vcpuid, val - rdtsc());
 		break;
 	case MSR_TSC_AUX:
-		if (vmx_have_msr_tsc_aux(vmx))
+		if (vmx_have_msr_tsc_aux)
 			/*
 			 * vmx_msr_guest_enter_tsc_aux() will apply this
 			 * value when it is called immediately before guest