[PATCH 16/17] KVM: arm64: Alloc pkvm_hyp_vcpu using pKVM heap allocator
Vincent Donnefort
vdonnefort at google.com
Wed May 20 08:26:49 PDT 2026
Transition the allocation of the hypervisor vCPU state structure
(pkvm_hyp_vcpu) from the host to the hypervisor using the new pKVM heap
allocator (hyp_alloc()).
Previously, the host was responsible for calculating the size of,
allocating, and donating memory for pkvm_hyp_vcpu during VM creation.
With the heap allocator in place, the hypervisor now allocates this
structure dynamically at EL2.
Use the pkvm_call_hyp_req() wrapper in the host to invoke
__pkvm_create_hyp_vcpu, which automatically handles any top-up requests
if the hypervisor runs out of heap memory during allocation.
Signed-off-by: Vincent Donnefort <vdonnefort at google.com>
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 15c5378b70a0..d7286f2944f3 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -268,7 +268,6 @@ typedef u16 pkvm_handle_t;
struct kvm_protected_vm {
pkvm_handle_t handle;
- struct kvm_hyp_memcache teardown_mc;
struct kvm_hyp_memcache stage2_teardown_mc;
bool is_protected;
bool is_created;
diff --git a/arch/arm64/kvm/hyp/hyp-constants.c b/arch/arm64/kvm/hyp/hyp-constants.c
index 501ab35a3840..b2caae21f271 100644
--- a/arch/arm64/kvm/hyp/hyp-constants.c
+++ b/arch/arm64/kvm/hyp/hyp-constants.c
@@ -7,6 +7,5 @@
int main(void)
{
DEFINE(STRUCT_HYP_PAGE_SIZE, sizeof(struct hyp_page));
- DEFINE(PKVM_HYP_VCPU_SIZE, sizeof(struct pkvm_hyp_vcpu));
return 0;
}
diff --git a/arch/arm64/kvm/hyp/include/nvhe/pkvm.h b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h
index 8e930c8729af..cfb6e409bf49 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/pkvm.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h
@@ -83,8 +83,7 @@ void pkvm_hyp_vm_table_init(void *tbl);
int __pkvm_reserve_vm(void);
void __pkvm_unreserve_vm(pkvm_handle_t handle);
int __pkvm_init_vm(struct kvm *host_kvm, void *pgd);
-int __pkvm_init_vcpu(pkvm_handle_t handle, struct kvm_vcpu *host_vcpu,
- unsigned long vcpu_hva);
+int __pkvm_init_vcpu(pkvm_handle_t handle, struct kvm_vcpu *host_vcpu);
int __pkvm_reclaim_dying_guest_page(pkvm_handle_t handle, u64 gfn);
int __pkvm_start_teardown_vm(pkvm_handle_t handle);
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index ebd6b5c09928..8d7e44e657eb 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -586,10 +586,9 @@ static void handle___pkvm_init_vcpu(struct kvm_cpu_context *host_ctxt)
{
DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 2);
- DECLARE_REG(unsigned long, vcpu_hva, host_ctxt, 3);
host_vcpu = kern_hyp_va(host_vcpu);
- cpu_reg(host_ctxt, 1) = __pkvm_init_vcpu(handle, host_vcpu, vcpu_hva);
+ errno_to_smccc(__pkvm_init_vcpu(handle, host_vcpu), host_ctxt);
}
static void handle___pkvm_vcpu_in_poison_fault(struct kvm_cpu_context *host_ctxt)
diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c
index 7405626e103a..5932e8afce3e 100644
--- a/arch/arm64/kvm/hyp/nvhe/pkvm.c
+++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c
@@ -645,30 +645,6 @@ static size_t pkvm_get_hyp_vm_size(unsigned int nr_vcpus)
size_mul(sizeof(struct pkvm_hyp_vcpu *), nr_vcpus));
}
-static void *map_donated_memory_noclear(unsigned long host_va, size_t size)
-{
- void *va = (void *)kern_hyp_va(host_va);
-
- if (!PAGE_ALIGNED(va))
- return NULL;
-
- if (__pkvm_host_donate_hyp(hyp_virt_to_pfn(va),
- PAGE_ALIGN(size) >> PAGE_SHIFT))
- return NULL;
-
- return va;
-}
-
-static void *map_donated_memory(unsigned long host_va, size_t size)
-{
- void *va = map_donated_memory_noclear(host_va, size);
-
- if (va)
- memset(va, 0, size);
-
- return va;
-}
-
static void __unmap_donated_memory(void *va, size_t size)
{
kvm_flush_dcache_to_poc(va, size);
@@ -676,15 +652,6 @@ static void __unmap_donated_memory(void *va, size_t size)
PAGE_ALIGN(size) >> PAGE_SHIFT));
}
-static void unmap_donated_memory(void *va, size_t size)
-{
- if (!va)
- return;
-
- memset(va, 0, size);
- __unmap_donated_memory(va, size);
-}
-
static void unmap_donated_memory_noclear(void *va, size_t size)
{
if (!va)
@@ -880,16 +847,15 @@ static int register_hyp_vcpu(struct pkvm_hyp_vm *hyp_vm,
return 0;
}
-int __pkvm_init_vcpu(pkvm_handle_t handle, struct kvm_vcpu *host_vcpu,
- unsigned long vcpu_hva)
+int __pkvm_init_vcpu(pkvm_handle_t handle, struct kvm_vcpu *host_vcpu)
{
struct pkvm_hyp_vcpu *hyp_vcpu;
struct pkvm_hyp_vm *hyp_vm;
int ret;
- hyp_vcpu = map_donated_memory(vcpu_hva, sizeof(*hyp_vcpu));
+ hyp_vcpu = hyp_alloc(sizeof(*hyp_vcpu));
if (!hyp_vcpu)
- return -ENOMEM;
+ return hyp_alloc_errno();
hyp_spin_lock(&vm_table_lock);
@@ -910,22 +876,10 @@ int __pkvm_init_vcpu(pkvm_handle_t handle, struct kvm_vcpu *host_vcpu,
}
unlock:
hyp_spin_unlock(&vm_table_lock);
-
if (ret)
- unmap_donated_memory(hyp_vcpu, sizeof(*hyp_vcpu));
- return ret;
-}
-
-static void
-teardown_donated_memory(struct kvm_hyp_memcache *mc, void *addr, size_t size)
-{
- size = PAGE_ALIGN(size);
- memset(addr, 0, size);
-
- for (void *start = addr; start < addr + size; start += PAGE_SIZE)
- push_hyp_memcache(mc, start, hyp_virt_to_phys);
+ hyp_free(hyp_vcpu);
- unmap_donated_memory_noclear(addr, size);
+ return ret;
}
int __pkvm_reclaim_dying_guest_page(pkvm_handle_t handle, u64 gfn)
@@ -977,7 +931,7 @@ int __pkvm_start_teardown_vm(pkvm_handle_t handle)
int __pkvm_finalize_teardown_vm(pkvm_handle_t handle)
{
- struct kvm_hyp_memcache *mc, *stage2_mc;
+ struct kvm_hyp_memcache *stage2_mc;
struct pkvm_hyp_vm *hyp_vm;
struct kvm *host_kvm;
unsigned int idx;
@@ -998,7 +952,6 @@ int __pkvm_finalize_teardown_vm(pkvm_handle_t handle)
hyp_spin_unlock(&vm_table_lock);
/* Reclaim guest pages (including page-table pages) */
- mc = &host_kvm->arch.pkvm.teardown_mc;
stage2_mc = &host_kvm->arch.pkvm.stage2_teardown_mc;
reclaim_pgtable_pages(hyp_vm, stage2_mc);
unpin_host_vcpus(hyp_vm->vcpus, hyp_vm->kvm.created_vcpus);
@@ -1020,7 +973,7 @@ int __pkvm_finalize_teardown_vm(pkvm_handle_t handle)
unmap_donated_memory_noclear(addr, PAGE_SIZE);
}
- teardown_donated_memory(mc, hyp_vcpu, sizeof(*hyp_vcpu));
+ hyp_free(hyp_vcpu);
}
hyp_free(hyp_vm);
diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c
index 8fc2e954d382..5e389099d1b6 100644
--- a/arch/arm64/kvm/pkvm.c
+++ b/arch/arm64/kvm/pkvm.c
@@ -178,28 +178,19 @@ static void __pkvm_destroy_hyp_vm(struct kvm *kvm)
kvm->arch.pkvm.handle = 0;
kvm->arch.pkvm.is_created = false;
- free_hyp_memcache(&kvm->arch.pkvm.teardown_mc);
free_hyp_memcache(&kvm->arch.pkvm.stage2_teardown_mc);
}
static int __pkvm_create_hyp_vcpu(struct kvm_vcpu *vcpu)
{
- size_t hyp_vcpu_sz = PAGE_ALIGN(PKVM_HYP_VCPU_SIZE);
pkvm_handle_t handle = vcpu->kvm->arch.pkvm.handle;
- void *hyp_vcpu;
int ret;
init_hyp_stage2_memcache(&vcpu->arch.pkvm_memcache);
- hyp_vcpu = alloc_pages_exact(hyp_vcpu_sz, GFP_KERNEL_ACCOUNT);
- if (!hyp_vcpu)
- return -ENOMEM;
-
- ret = kvm_call_hyp_nvhe(__pkvm_init_vcpu, handle, vcpu, hyp_vcpu);
+ ret = pkvm_call_hyp_req(__pkvm_init_vcpu, handle, vcpu);
if (!ret)
vcpu_set_flag(vcpu, VCPU_PKVM_FINALIZED);
- else
- free_pages_exact(hyp_vcpu, hyp_vcpu_sz);
return ret;
}
--
2.54.0.631.ge1b05301d1-goog
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