KVM: arm64: Distinct pKVM teardown memcache for stage-2

In order to account for memory dedicated to the stage-2 page-tables, use
a separated memcache when tearing down the VM. Meanwhile rename
reclaim_guest_pages to reflect the fact it only reclaim page-table
pages.

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250313114038.1502357-3-vdonnefort@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 12691ae23d4cfc9ec593518729d11fca33f9c429..ace3969e8106fee9e8ae028a0ea9617eafc29346 100644 (file)
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -246,6 +246,7 @@ typedef unsigned int 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 enabled;
 };
 

diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
index 978f38c386ee53cb813055d5409820f5a57b2dcc..ea0a704da9b8962cda1c143084161ec44fe968c5 100644 (file)
--- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
@@ -56,7 +56,7 @@ void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt);
 
 int hyp_pin_shared_mem(void *from, void *to);
 void hyp_unpin_shared_mem(void *from, void *to);
-void reclaim_guest_pages(struct pkvm_hyp_vm *vm, struct kvm_hyp_memcache *mc);
+void reclaim_pgtable_pages(struct pkvm_hyp_vm *vm, struct kvm_hyp_memcache *mc);
 int refill_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages,
                    struct kvm_hyp_memcache *host_mc);
 

diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 19c3c631708ce389704ad293cb2ec347735afa85..f34f11c720d70792afdc279a469a92003dbe5d38 100644 (file)
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -266,7 +266,7 @@ int kvm_guest_prepare_stage2(struct pkvm_hyp_vm *vm, void *pgd)
        return 0;
 }
 
-void reclaim_guest_pages(struct pkvm_hyp_vm *vm, struct kvm_hyp_memcache *mc)
+void reclaim_pgtable_pages(struct pkvm_hyp_vm *vm, struct kvm_hyp_memcache *mc)
 {
        struct hyp_page *page;
        void *addr;

diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c
index 3927fe52a3dde8f59ddb996d674dd252630613a3..ac85bc51b8d3110192851faeaa07c706e4acf5c5 100644 (file)
--- a/arch/arm64/kvm/hyp/nvhe/pkvm.c
+++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c
@@ -678,7 +678,7 @@ teardown_donated_memory(struct kvm_hyp_memcache *mc, void *addr, size_t size)
 
 int __pkvm_teardown_vm(pkvm_handle_t handle)
 {
-       struct kvm_hyp_memcache *mc;
+       struct kvm_hyp_memcache *mc, *stage2_mc;
        struct pkvm_hyp_vm *hyp_vm;
        struct kvm *host_kvm;
        unsigned int idx;
@@ -706,10 +706,10 @@ int __pkvm_teardown_vm(pkvm_handle_t handle)
 
        /* Reclaim guest pages (including page-table pages) */
        mc = &host_kvm->arch.pkvm.teardown_mc;
-       reclaim_guest_pages(hyp_vm, 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->nr_vcpus);
 
-       /* Push the metadata pages to the teardown memcache */
        for (idx = 0; idx < hyp_vm->nr_vcpus; ++idx) {
                struct pkvm_hyp_vcpu *hyp_vcpu = hyp_vm->vcpus[idx];
                struct kvm_hyp_memcache *vcpu_mc = &hyp_vcpu->vcpu.arch.pkvm_memcache;
@@ -717,7 +717,7 @@ int __pkvm_teardown_vm(pkvm_handle_t handle)
                while (vcpu_mc->nr_pages) {
                        void *addr = pop_hyp_memcache(vcpu_mc, hyp_phys_to_virt);
 
-                       push_hyp_memcache(mc, addr, hyp_virt_to_phys);
+                       push_hyp_memcache(stage2_mc, addr, hyp_virt_to_phys);
                        unmap_donated_memory_noclear(addr, PAGE_SIZE);
                }
 

diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c
index 930b677eb9b0a76e3c3f211abecdf5f3e59ae82c..19921ca407c617a300eaf6e5137da0e7aab47923 100644 (file)
--- a/arch/arm64/kvm/pkvm.c
+++ b/arch/arm64/kvm/pkvm.c
@@ -111,6 +111,7 @@ static void __pkvm_destroy_hyp_vm(struct kvm *host_kvm)
 
        host_kvm->arch.pkvm.handle = 0;
        free_hyp_memcache(&host_kvm->arch.pkvm.teardown_mc);
+       free_hyp_memcache(&host_kvm->arch.pkvm.stage2_teardown_mc);
 }
 
 /*