Commit e5fda4bb authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86: Move uret MSR slot management to common x86 



Now that SVM and VMX both probe MSRs before "defining" user return slots
for them, consolidate the code for probe+define into common x86 and
eliminate the odd behavior of having the vendor code define the slot for
a given MSR.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210504171734.1434054-14-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 9cc39a5a

arch/x86/include/asm/kvm_host.h

+1 −2
Original line number Diff line number Diff line
@@ -1777,9 +1777,8 @@ int kvm_pv_send_ipi(struct kvm *kvm, unsigned long ipi_bitmap_low, 
		    unsigned long ipi_bitmap_high, u32 min,

		    unsigned long icr, int op_64_bit);



void kvm_define_user_return_msr(unsigned index, u32 msr);

int kvm_add_user_return_msr(u32 msr);

int kvm_find_user_return_msr(u32 msr);

int kvm_probe_user_return_msr(u32 msr);

int kvm_set_user_return_msr(unsigned index, u64 val, u64 mask);



u64 kvm_scale_tsc(struct kvm_vcpu *vcpu, u64 tsc);

arch/x86/kvm/svm/svm.c

+1 −4
Original line number Diff line number Diff line
@@ -959,10 +959,7 @@ static __init int svm_hardware_setup(void) 
		kvm_tsc_scaling_ratio_frac_bits = 32;

	}



	if (!kvm_probe_user_return_msr(MSR_TSC_AUX)) {

		tsc_aux_uret_slot = 0;

		kvm_define_user_return_msr(tsc_aux_uret_slot, MSR_TSC_AUX);

	}

	tsc_aux_uret_slot = kvm_add_user_return_msr(MSR_TSC_AUX);



	/* Check for pause filtering support */

	if (!boot_cpu_has(X86_FEATURE_PAUSEFILTER)) {

arch/x86/kvm/vmx/vmx.c

+4 −15
Original line number Diff line number Diff line
@@ -454,9 +454,6 @@ static inline void vmx_segment_cache_clear(struct vcpu_vmx *vmx) 


static unsigned long host_idt_base;



/* Number of user return MSRs that are actually supported in hardware. */

static int vmx_nr_uret_msrs;



#if IS_ENABLED(CONFIG_HYPERV)

static bool __read_mostly enlightened_vmcs = true;

module_param(enlightened_vmcs, bool, 0444);
@@ -1218,7 +1215,7 @@ void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu) 
	 */

	if (!vmx->guest_uret_msrs_loaded) {

		vmx->guest_uret_msrs_loaded = true;

		for (i = 0; i < vmx_nr_uret_msrs; ++i) {

		for (i = 0; i < kvm_nr_uret_msrs; ++i) {

			if (!vmx->guest_uret_msrs[i].load_into_hardware)

				continue;
@@ -6921,7 +6918,7 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu) 
			goto free_vpid;

	}



	for (i = 0; i < vmx_nr_uret_msrs; ++i) {

	for (i = 0; i < kvm_nr_uret_msrs; ++i) {

		vmx->guest_uret_msrs[i].data = 0;

		vmx->guest_uret_msrs[i].mask = -1ull;

	}
@@ -7810,20 +7807,12 @@ static __init void vmx_setup_user_return_msrs(void) 
		MSR_EFER, MSR_TSC_AUX, MSR_STAR,

		MSR_IA32_TSX_CTRL,

	};

	u32 msr;

	int i;



	BUILD_BUG_ON(ARRAY_SIZE(vmx_uret_msrs_list) != MAX_NR_USER_RETURN_MSRS);



	for (i = 0; i < ARRAY_SIZE(vmx_uret_msrs_list); ++i) {

		msr = vmx_uret_msrs_list[i];



		if (kvm_probe_user_return_msr(msr))

			continue;



		kvm_define_user_return_msr(vmx_nr_uret_msrs, msr);

		vmx_nr_uret_msrs++;

	}

	for (i = 0; i < ARRAY_SIZE(vmx_uret_msrs_list); ++i)

		kvm_add_user_return_msr(vmx_uret_msrs_list[i]);

}



static __init int hardware_setup(void)

arch/x86/kvm/x86.c

+11 −8
Original line number Diff line number Diff line
@@ -336,7 +336,7 @@ static void kvm_on_user_return(struct user_return_notifier *urn) 
	}

}



int kvm_probe_user_return_msr(u32 msr)

static int kvm_probe_user_return_msr(u32 msr)

{

	u64 val;

	int ret;
@@ -350,16 +350,18 @@ int kvm_probe_user_return_msr(u32 msr) 
	preempt_enable();

	return ret;

}

EXPORT_SYMBOL_GPL(kvm_probe_user_return_msr);



void kvm_define_user_return_msr(unsigned slot, u32 msr)

int kvm_add_user_return_msr(u32 msr)

{

	BUG_ON(slot >= KVM_MAX_NR_USER_RETURN_MSRS);

	kvm_uret_msrs_list[slot] = msr;

	if (slot >= kvm_nr_uret_msrs)

		kvm_nr_uret_msrs = slot + 1;

	BUG_ON(kvm_nr_uret_msrs >= KVM_MAX_NR_USER_RETURN_MSRS);



	if (kvm_probe_user_return_msr(msr))

		return -1;



	kvm_uret_msrs_list[kvm_nr_uret_msrs] = msr;

	return kvm_nr_uret_msrs++;

}

EXPORT_SYMBOL_GPL(kvm_define_user_return_msr);

EXPORT_SYMBOL_GPL(kvm_add_user_return_msr);



int kvm_find_user_return_msr(u32 msr)

{
@@ -8132,6 +8134,7 @@ int kvm_arch_init(void *opaque) 
		printk(KERN_ERR "kvm: failed to allocate percpu kvm_user_return_msrs\n");

		goto out_free_x86_emulator_cache;

	}

	kvm_nr_uret_msrs = 0;



	r = kvm_mmu_module_init();

	if (r)