diff mbox

[PART2,v3,10/11] svm: Introduce AMD IOMMU avic_ga_log_notifier

Message ID 1468231899-6987-11-git-send-email-suravee.suthikulpanit@amd.com
State Superseded
Headers show

Commit Message

Suthikulpanit, Suravee July 11, 2016, 10:11 a.m. UTC 
From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>


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

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>

---
 arch/x86/include/asm/kvm_host.h |  2 ++
 arch/x86/kvm/svm.c              | 60 +++++++++++++++++++++++++++++++++++++++--
 2 files changed, 60 insertions(+), 2 deletions(-)

-- 
1.9.1

Comments

Suthikulpanit, Suravee July 13, 2016, 8:53 a.m. UTC | #1 
Hi Radim,

Again, sorry for possible confusion from the mis-use of the word ga_tag 
for parameter naming in different places. Please see my reply for the 
patch 07/11 for more detail.

On 07/12/2016 02:09 AM, Radim Krčmář wrote:
> 2016-07-11 05:11-0500, Suravee Suthikulpanit:

>> From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>

>>

>> This patch introduces avic_ga_log_notifier, which will be called

>> by IOMMU driver whenever it handles the Guest vAPIC (GA) log entry.

>>

>> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>

>> ---

>> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c

>> @@ -928,6 +930,45 @@ static void svm_disable_lbrv(struct vcpu_svm *svm)

>> +static int avic_ga_log_notifier(int avic_tag, int vcpu_id, int vec)

>> +{

>> +	unsigned long flags;

>> +	struct kvm_arch *ka = NULL;

>> +	struct kvm_vcpu *vcpu = NULL;

>> +	struct vcpu_svm *svm = NULL;

>> +

>> +	pr_debug("SVM: %s: avic_tag=%#x, vcpu_id=%#x, vec=%#x\n",

>> +		 __func__, avic_tag, vcpu_id, vec);

>> +

>> +	spin_lock_irqsave(&svm_vm_data_hash_lock, flags);

>> +	hash_for_each_possible(svm_vm_data_hash, ka, hnode, avic_tag) {

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

>

> iommu_handle_ga_guest_nr_entry(), the caller, already performed a hash

> lookup to get ir_data.  Cannot we store the vcpu pointer in ir_data, to

> avoid a second hash lookup and a vcpu lookup?

>

> Thanks.

>


The iommu_handle_ga_guest_nr_entry() has the look up logic to map ga_tag 
back to an ir_data in order to see if there are any pending interrupts 
targeting a particular VCPU of a particular VM.

The look up in the avic_ga_log_notifier() is for SVM to map VM_ID to the 
struct kvm_arch.

Thanks,
Suravee
diff mbox

Patch

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 69e62862..fe1c5c3 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -776,9 +776,11 @@  struct kvm_arch {
 	bool disabled_lapic_found;
 
 	/* Struct members for AVIC */
+	u32 avic_tag;
 	u32 ldr_mode;
 	struct page *avic_logical_id_table_page;
 	struct page *avic_physical_id_table_page;
+	struct hlist_node hnode;
 };
 
 struct kvm_vm_stat {
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 16ef31b..968047e 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -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>
@@ -928,6 +930,45 @@  static void svm_disable_lbrv(struct vcpu_svm *svm)
 	set_msr_interception(msrpm, MSR_IA32_LASTINTTOIP, 0, 0);
 }
 
+#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;
+
+static int avic_ga_log_notifier(int avic_tag, int vcpu_id, int vec)
+{
+	unsigned long flags;
+	struct kvm_arch *ka = NULL;
+	struct kvm_vcpu *vcpu = NULL;
+	struct vcpu_svm *svm = NULL;
+
+	pr_debug("SVM: %s: avic_tag=%#x, vcpu_id=%#x, vec=%#x\n",
+		 __func__, avic_tag, vcpu_id, vec);
+
+	spin_lock_irqsave(&svm_vm_data_hash_lock, flags);
+	hash_for_each_possible(svm_vm_data_hash, ka, hnode, avic_tag) {
+		struct kvm *kvm = container_of(ka, struct kvm, arch);
+
+		vcpu = kvm_get_vcpu_by_id(kvm, vcpu_id);
+		break;
+	}
+	spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags);
+
+	if (!vcpu)
+		return 0;
+
+	svm = to_svm(vcpu);
+
+	/* 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;
@@ -986,10 +1027,15 @@  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;
@@ -1282,16 +1328,22 @@  static int avic_init_backing_page(struct kvm_vcpu *vcpu)
 
 static void avic_vm_destroy(struct kvm *kvm)
 {
+	unsigned long flags;
 	struct kvm_arch *vm_data = &kvm->arch;
 
 	if (vm_data->avic_logical_id_table_page)
 		__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;
@@ -1316,6 +1368,10 @@  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_tag);
+	spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags);
+
 	return 0;
 
 free_avic: