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Commit 5881f737 authored by Suravee Suthikulpanit's avatar Suravee Suthikulpanit Committed by Paolo Bonzini
Browse files

svm: Introduce AMD IOMMU avic_ga_log_notifier 



This patch introduces avic_ga_log_notifier, which will be called
by IOMMU driver whenever it handles the Guest vAPIC (GA) log entry.

Reviewed-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: default avatarSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 5ea11f2b

arch/x86/include/asm/kvm_host.h

+1 −0
Original line number Diff line number Diff line
@@ -785,6 +785,7 @@ struct kvm_arch { 
	u32 ldr_mode;

	struct page *avic_logical_id_table_page;

	struct page *avic_physical_id_table_page;

	struct hlist_node hnode;



	bool x2apic_format;

	bool x2apic_broadcast_quirk_disabled;

arch/x86/kvm/svm.c

+68 −2
Original line number Diff line number Diff line
@@ -34,6 +34,8 @@ 
#include <linux/sched.h>

#include <linux/trace_events.h>

#include <linux/slab.h>

#include <linux/amd-iommu.h>

#include <linux/hashtable.h>



#include <asm/apic.h>

#include <asm/perf_event.h>
@@ -945,6 +947,55 @@ static void svm_disable_lbrv(struct vcpu_svm *svm) 
	set_msr_interception(msrpm, MSR_IA32_LASTINTTOIP, 0, 0);

}



/* Note:

 * This hash table is used to map VM_ID to a struct kvm_arch,

 * when handling AMD IOMMU GALOG notification to schedule in

 * a particular vCPU.

 */

#define SVM_VM_DATA_HASH_BITS	8

DECLARE_HASHTABLE(svm_vm_data_hash, SVM_VM_DATA_HASH_BITS);

static spinlock_t svm_vm_data_hash_lock;



/* Note:

 * This function is called from IOMMU driver to notify

 * SVM to schedule in a particular vCPU of a particular VM.

 */

static int avic_ga_log_notifier(u32 ga_tag)

{

	unsigned long flags;

	struct kvm_arch *ka = NULL;

	struct kvm_vcpu *vcpu = NULL;

	u32 vm_id = AVIC_GATAG_TO_VMID(ga_tag);

	u32 vcpu_id = AVIC_GATAG_TO_VCPUID(ga_tag);



	pr_debug("SVM: %s: vm_id=%#x, vcpu_id=%#x\n", __func__, vm_id, vcpu_id);



	spin_lock_irqsave(&svm_vm_data_hash_lock, flags);

	hash_for_each_possible(svm_vm_data_hash, ka, hnode, vm_id) {

		struct kvm *kvm = container_of(ka, struct kvm, arch);

		struct kvm_arch *vm_data = &kvm->arch;



		if (vm_data->avic_vm_id != vm_id)

			continue;

		vcpu = kvm_get_vcpu_by_id(kvm, vcpu_id);

		break;

	}

	spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags);



	if (!vcpu)

		return 0;



	/* Note:

	 * At this point, the IOMMU should have already set the pending

	 * bit in the vAPIC backing page. So, we just need to schedule

	 * in the vcpu.

	 */

	if (vcpu->mode == OUTSIDE_GUEST_MODE)

		kvm_vcpu_wake_up(vcpu);



	return 0;

}



static __init int svm_hardware_setup(void)

{

	int cpu;
@@ -1003,10 +1054,15 @@ static __init int svm_hardware_setup(void) 
	if (avic) {

		if (!npt_enabled ||

		    !boot_cpu_has(X86_FEATURE_AVIC) ||

		    !IS_ENABLED(CONFIG_X86_LOCAL_APIC))

		    !IS_ENABLED(CONFIG_X86_LOCAL_APIC)) {

			avic = false;

		else

		} else {

			pr_info("AVIC enabled\n");



			hash_init(svm_vm_data_hash);

			spin_lock_init(&svm_vm_data_hash_lock);

			amd_iommu_register_ga_log_notifier(&avic_ga_log_notifier);

		}

	}



	return 0;
@@ -1327,6 +1383,7 @@ static inline int avic_free_vm_id(int id) 


static void avic_vm_destroy(struct kvm *kvm)

{

	unsigned long flags;

	struct kvm_arch *vm_data = &kvm->arch;



	avic_free_vm_id(vm_data->avic_vm_id);
@@ -1335,10 +1392,15 @@ static void avic_vm_destroy(struct kvm *kvm) 
		__free_page(vm_data->avic_logical_id_table_page);

	if (vm_data->avic_physical_id_table_page)

		__free_page(vm_data->avic_physical_id_table_page);



	spin_lock_irqsave(&svm_vm_data_hash_lock, flags);

	hash_del(&vm_data->hnode);

	spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags);

}



static int avic_vm_init(struct kvm *kvm)

{

	unsigned long flags;

	int err = -ENOMEM;

	struct kvm_arch *vm_data = &kvm->arch;

	struct page *p_page;
@@ -1367,6 +1429,10 @@ static int avic_vm_init(struct kvm *kvm) 
	vm_data->avic_logical_id_table_page = l_page;

	clear_page(page_address(l_page));



	spin_lock_irqsave(&svm_vm_data_hash_lock, flags);

	hash_add(svm_vm_data_hash, &vm_data->hnode, vm_data->avic_vm_id);

	spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags);



	return 0;



free_avic: