KVM: SVM: Move AVIC Physical ID table allocation to vcpu_precreate()

With support for 4k vCPUs in x2AVIC, the size of the AVIC Physical ID
table is expanded from a single 4k page to a maximum of 8 contiguous 4k
pages. The actual number of pages allocated depends on the maximum
possible APIC ID in the guest, which is only known by the time the first
vCPU is created. In preparation for supporting a dynamic AVIC Physical
ID table size, move its allocation to vcpu_precreate().

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Naveen N Rao (AMD) <naveen@kernel.org>
Link: https://lore.kernel.org/r/7dc764e0af7f01440bbac3d9215ed174027c2384.1757009416.git.naveen@kernel.org
[sean: drop enable_apicv check from svm_vcpu_precreate()]
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index b31be39a118fc8ba496f4b4a3934747a49877d6c..9866ef73501ef9b1b1c17243706485a3138c29ca 100644 (file)
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -264,6 +264,23 @@ int avic_ga_log_notifier(u32 ga_tag)
        return 0;
 }
 
+int avic_alloc_physical_id_table(struct kvm *kvm)
+{
+       struct kvm_svm *kvm_svm = to_kvm_svm(kvm);
+
+       if (!irqchip_in_kernel(kvm) || !enable_apicv)
+               return 0;
+
+       if (kvm_svm->avic_physical_id_table)
+               return 0;
+
+       kvm_svm->avic_physical_id_table = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
+       if (!kvm_svm->avic_physical_id_table)
+               return -ENOMEM;
+
+       return 0;
+}
+
 void avic_vm_destroy(struct kvm *kvm)
 {
        unsigned long flags;
@@ -291,10 +308,6 @@ int avic_vm_init(struct kvm *kvm)
        if (!enable_apicv)
                return 0;
 
-       kvm_svm->avic_physical_id_table = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
-       if (!kvm_svm->avic_physical_id_table)
-               goto free_avic;
-
        kvm_svm->avic_logical_id_table = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
        if (!kvm_svm->avic_logical_id_table)
                goto free_avic;

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index dadb562bd4b9d81ef11dbedd297092dfc114f334..f14709a511aa4ed9d2a1f8ae5170e9389791face 100644 (file)
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1207,6 +1207,11 @@ void svm_switch_vmcb(struct vcpu_svm *svm, struct kvm_vmcb_info *target_vmcb)
        svm->vmcb = target_vmcb->ptr;
 }
 
+static int svm_vcpu_precreate(struct kvm *kvm)
+{
+       return avic_alloc_physical_id_table(kvm);
+}
+
 static int svm_vcpu_create(struct kvm_vcpu *vcpu)
 {
        struct vcpu_svm *svm;
@@ -5016,6 +5021,7 @@ struct kvm_x86_ops svm_x86_ops __initdata = {
        .emergency_disable_virtualization_cpu = svm_emergency_disable_virtualization_cpu,
        .has_emulated_msr = svm_has_emulated_msr,
 
+       .vcpu_precreate = svm_vcpu_precreate,
        .vcpu_create = svm_vcpu_create,
        .vcpu_free = svm_vcpu_free,
        .vcpu_reset = svm_vcpu_reset,

diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index e4b04f435b3d03bb107ccd5aa9ea7aa2ece2ad3e..6765a5e433cea3b92e0aa77db81e18bcdc29efef 100644 (file)
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -806,6 +806,7 @@ extern struct kvm_x86_nested_ops svm_nested_ops;
 
 bool __init avic_hardware_setup(void);
 int avic_ga_log_notifier(u32 ga_tag);
+int avic_alloc_physical_id_table(struct kvm *kvm);
 void avic_vm_destroy(struct kvm *kvm);
 int avic_vm_init(struct kvm *kvm);
 void avic_init_vmcb(struct vcpu_svm *svm, struct vmcb *vmcb);