Merge tag 'kvm-x86-misc-6.18' of https://github.com/kvm-x86/linux into HEAD

KVM x86 changes for 6.18

 - Don't (re)check L1 intercepts when completing userspace I/O to fix a flaw
   where a misbehaving usersepace (a.k.a. syzkaller) could swizzle L1's
   intercepts and trigger a variety of WARNs in KVM.

 - Emulate PERF_CNTR_GLOBAL_STATUS_SET for PerfMonV2 guests, as the MSR is
   supposed to exist for v2 PMUs.

 - Allow Centaur CPU leaves (base 0xC000_0000) for Zhaoxin CPUs.

 - Clean up KVM's vector hashing code for delivering lowest priority IRQs.

 - Clean up the fastpath handler code to only handle IPIs and WRMSRs that are
   actually "fast", as opposed to handling those that KVM _hopes_ are fast, and
   in the process of doing so add fastpath support for TSC_DEADLINE writes on
   AMD CPUs.

 - Clean up a pile of PMU code in anticipation of adding support for mediated
   vPMUs.

 - Add support for the immediate forms of RDMSR and WRMSRNS, sans full
   emulator support (KVM should never need to emulate the MSRs outside of
   forced emulation and other contrived testing scenarios).

 - Clean up the MSR APIs in preparation for CET and FRED virtualization, as
   well as mediated vPMU support.

 - Rejecting a fully in-kernel IRQCHIP if EOIs are protected, i.e. for TDX VMs,
   as KVM can't faithfully emulate an I/O APIC for such guests.

 - KVM_REQ_MSR_FILTER_CHANGED into a generic RECALC_INTERCEPTS in preparation
   for mediated vPMU support, as KVM will need to recalculate MSR intercepts in
   response to PMU refreshes for guests with mediated vPMUs.

 - Misc cleanups and minor fixes.

1 files changed, 21 insertions, 9 deletions

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index b8504f1fe4ef..81db26b2a1bd 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1008,7 +1008,7 @@ static void svm_recalc_instruction_intercepts(struct kvm_vcpu *vcpu)
 	}
 }
 
-static void svm_recalc_intercepts_after_set_cpuid(struct kvm_vcpu *vcpu)
+static void svm_recalc_intercepts(struct kvm_vcpu *vcpu)
 {
 	svm_recalc_instruction_intercepts(vcpu);
 	svm_recalc_msr_intercepts(vcpu);
@@ -1156,7 +1156,7 @@ static void init_vmcb(struct kvm_vcpu *vcpu, bool init_event)
 
 	svm_hv_init_vmcb(vmcb);
 
-	svm_recalc_intercepts_after_set_cpuid(vcpu);
+	kvm_make_request(KVM_REQ_RECALC_INTERCEPTS, vcpu);
 
 	vmcb_mark_all_dirty(vmcb);
 
@@ -4093,17 +4093,27 @@ static int svm_vcpu_pre_run(struct kvm_vcpu *vcpu)
 static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
+	struct vmcb_control_area *control = &svm->vmcb->control;
+
+	/*
+	 * Next RIP must be provided as IRQs are disabled, and accessing guest
+	 * memory to decode the instruction might fault, i.e. might sleep.
+	 */
+	if (!nrips || !control->next_rip)
+		return EXIT_FASTPATH_NONE;
 
 	if (is_guest_mode(vcpu))
 		return EXIT_FASTPATH_NONE;
 
-	switch (svm->vmcb->control.exit_code) {
+	switch (control->exit_code) {
 	case SVM_EXIT_MSR:
-		if (!svm->vmcb->control.exit_info_1)
+		if (!control->exit_info_1)
 			break;
-		return handle_fastpath_set_msr_irqoff(vcpu);
+		return handle_fastpath_wrmsr(vcpu);
 	case SVM_EXIT_HLT:
 		return handle_fastpath_hlt(vcpu);
+	case SVM_EXIT_INVD:
+		return handle_fastpath_invd(vcpu);
 	default:
 		break;
 	}
@@ -4380,8 +4390,6 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 
 	if (sev_guest(vcpu->kvm))
 		sev_vcpu_after_set_cpuid(svm);
-
-	svm_recalc_intercepts_after_set_cpuid(vcpu);
 }
 
 static bool svm_has_wbinvd_exit(void)
@@ -5083,7 +5091,7 @@ struct kvm_x86_ops svm_x86_ops __initdata = {
 
 	.apic_init_signal_blocked = svm_apic_init_signal_blocked,
 
-	.recalc_msr_intercepts = svm_recalc_msr_intercepts,
+	.recalc_intercepts = svm_recalc_intercepts,
 	.complete_emulated_msr = svm_complete_emulated_msr,
 
 	.vcpu_deliver_sipi_vector = svm_vcpu_deliver_sipi_vector,
@@ -5213,8 +5221,12 @@ static __init void svm_set_cpu_caps(void)
 	/* CPUID 0x8000001F (SME/SEV features) */
 	sev_set_cpu_caps();
 
-	/* Don't advertise Bus Lock Detect to guest if SVM support is absent */
+	/*
+	 * Clear capabilities that are automatically configured by common code,
+	 * but that require explicit SVM support (that isn't yet implemented).
+	 */
 	kvm_cpu_cap_clear(X86_FEATURE_BUS_LOCK_DETECT);
+	kvm_cpu_cap_clear(X86_FEATURE_MSR_IMM);
 }
 
 static __init int svm_hardware_setup(void)