[RFC PATCH v3 26/59] KVM: x86: Introduce vm_teardown() hook in kvm_arch_vm_destroy()

isaku.yamahata
2021-11-25T00:21:43Z

From: Sean Christopherson <sean.j.christopherson@intel.com>

Add a second kvm_x86_ops hook in kvm_arch_vm_destroy() to support TDX's
destruction path, which needs to first put the VM into a teardown state,
then free per-vCPU resource, and finally free per-VM resources.

Note, this knowingly creates a discrepancy in nomenclature for SVM as
svm_vm_teardown() invokes avic_vm_destroy() and sev_vm_destroy().
Moving the now-misnamed functions or renaming them is left to a future
patch so as not to introduce a functional change for SVM.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
arch/x86/include/asm/kvm-x86-ops.h | 1 +
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/svm/svm.c | 5 +++--
arch/x86/kvm/vmx/vmx.c | 7 +++++++
arch/x86/kvm/x86.c | 3 ++-
5 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 30754f2b8a99..1009541fd6c2 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -20,6 +20,7 @@ KVM_X86_OP(has_emulated_msr)
KVM_X86_OP(vcpu_after_set_cpuid)
KVM_X86_OP(is_vm_type_supported)
KVM_X86_OP(vm_init)
+KVM_X86_OP_NULL(vm_teardown)
KVM_X86_OP_NULL(vm_destroy)
KVM_X86_OP(vcpu_create)
KVM_X86_OP(vcpu_free)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 74c3c1629563..3bc5417f94ec 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1321,6 +1321,7 @@ struct kvm_x86_ops {
bool (*is_vm_type_supported)(unsigned long vm_type);
unsigned int vm_size;
int (*vm_init)(struct kvm *kvm);
+ void (*vm_teardown)(struct kvm *kvm);
void (*vm_destroy)(struct kvm *kvm);

/* Create, but do not attach this VCPU */
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 2ef77d4566a9..1bf410add13b 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4556,7 +4556,7 @@ static void svm_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)
sev_vcpu_deliver_sipi_vector(vcpu, vector);
}

-static void svm_vm_destroy(struct kvm *kvm)
+static void svm_vm_teardown(struct kvm *kvm)
{
avic_vm_destroy(kvm);
sev_vm_destroy(kvm);
@@ -4597,7 +4597,8 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.is_vm_type_supported = svm_is_vm_type_supported,
.vm_size = sizeof(struct kvm_svm),
.vm_init = svm_vm_init,
- .vm_destroy = svm_vm_destroy,
+ .vm_teardown = svm_vm_teardown,
+ .vm_destroy = NULL,

.prepare_guest_switch = svm_prepare_guest_switch,
.vcpu_load = svm_vcpu_load,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index f2905e00b063..5e4c6ac9fe69 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6890,6 +6890,11 @@ static int vmx_vm_init(struct kvm *kvm)
return 0;
}

+static void vmx_vm_destroy(struct kvm *kvm)
+{
+
+}
+
static int __init vmx_check_processor_compat(void)
{
struct vmcs_config vmcs_conf;
@@ -7513,6 +7518,8 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
.is_vm_type_supported = vmx_is_vm_type_supported,
.vm_size = sizeof(struct kvm_vmx),
.vm_init = vmx_vm_init,
+ .vm_teardown = NULL,
+ .vm_destroy = vmx_vm_destroy,

.vcpu_create = vmx_create_vcpu,
.vcpu_free = vmx_free_vcpu,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f2091c4b928a..88b55ddb22a7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11613,7 +11613,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
__x86_set_memory_region(kvm, TSS_PRIVATE_MEMSLOT, 0, 0);
mutex_unlock(&kvm->slots_lock);
}
- static_call_cond(kvm_x86_vm_destroy)(kvm);
+ static_call_cond(kvm_x86_vm_teardown)(kvm);
kvm_free_msr_filter(srcu_dereference_check(kvm->arch.msr_filter, &kvm->srcu, 1));
kvm_pic_destroy(kvm);
kvm_ioapic_destroy(kvm);
@@ -11624,6 +11624,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
kvm_page_track_cleanup(kvm);
kvm_xen_destroy_vm(kvm);
kvm_hv_destroy_vm(kvm);
+ static_call_cond(kvm_x86_vm_destroy)(kvm);
}

static void memslot_rmap_free(struct kvm_memory_slot *slot)
--
2.25.1