From: Fuad Tabba <tabba@xxxxxxxxxx>
Now that EL2 provides calls to create and destroy shadow VM structures,
plumb these into the KVM code at EL1 so that a shadow VM is created on
first vCPU run and destroyed later along with the 'struct kvm' at
teardown time.
Signed-off-by: Fuad Tabba <tabba@xxxxxxxxxx>
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_host.h | 6 ++
arch/arm64/include/asm/kvm_pkvm.h | 4 ++
arch/arm64/kvm/arm.c | 14 ++++
arch/arm64/kvm/hyp/hyp-constants.c | 3 +
arch/arm64/kvm/pkvm.c | 112 +++++++++++++++++++++++++++++
5 files changed, 139 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 41348ac728f9..e91456f63161 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -117,6 +117,12 @@ struct kvm_smccc_features {
struct kvm_protected_vm {
unsigned int shadow_handle;
+ struct mutex shadow_lock;
+
+ struct {
+ void *pgd;
+ void *shadow;
+ } hyp_donations;
};
struct kvm_arch {
diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h
index 11526e89fe5c..1dc7372950b1 100644
--- a/arch/arm64/include/asm/kvm_pkvm.h
+++ b/arch/arm64/include/asm/kvm_pkvm.h
@@ -14,6 +14,10 @@
#define HYP_MEMBLOCK_REGIONS 128
+int kvm_init_pvm(struct kvm *kvm);
+int kvm_shadow_create(struct kvm *kvm);
+void kvm_shadow_destroy(struct kvm *kvm);
+
extern struct memblock_region kvm_nvhe_sym(hyp_memory)[];
extern unsigned int kvm_nvhe_sym(hyp_memblock_nr);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index a9dd7ec38f38..66e1d37858f1 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -37,6 +37,7 @@
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_mmu.h>
+#include <asm/kvm_pkvm.h>
#include <asm/kvm_emulate.h>
#include <asm/sections.h>
@@ -150,6 +151,10 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
if (ret)
goto out_free_stage2_pgd;
+ ret = kvm_init_pvm(kvm);
+ if (ret)
+ goto out_free_stage2_pgd;
+
if (!zalloc_cpumask_var(&kvm->arch.supported_cpus, GFP_KERNEL))
goto out_free_stage2_pgd;
cpumask_copy(kvm->arch.supported_cpus, cpu_possible_mask);
@@ -185,6 +190,9 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
kvm_vgic_destroy(kvm);
+ if (is_protected_kvm_enabled())
+ kvm_shadow_destroy(kvm);
+
kvm_destroy_vcpus(kvm);
kvm_unshare_hyp(kvm, kvm + 1);
@@ -567,6 +575,12 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
if (ret)
return ret;
+ if (is_protected_kvm_enabled()) {
+ ret = kvm_shadow_create(kvm);
+ if (ret)
+ return ret;
+ }
+
if (!irqchip_in_kernel(kvm)) {
/*
* Tell the rest of the code that there are userspace irqchip
diff --git a/arch/arm64/kvm/hyp/hyp-constants.c b/arch/arm64/kvm/hyp/hyp-constants.c
index b3742a6691e8..eee79527f901 100644
--- a/arch/arm64/kvm/hyp/hyp-constants.c
+++ b/arch/arm64/kvm/hyp/hyp-constants.c
@@ -2,9 +2,12 @@
#include <linux/kbuild.h>
#include <nvhe/memory.h>
+#include <nvhe/pkvm.h>
int main(void)
{
DEFINE(STRUCT_HYP_PAGE_SIZE, sizeof(struct hyp_page));
+ DEFINE(KVM_SHADOW_VM_SIZE, sizeof(struct kvm_shadow_vm));
+ DEFINE(KVM_SHADOW_VCPU_STATE_SIZE, sizeof(struct kvm_shadow_vcpu_state));
return 0;
}
diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c
index 3947063cc3a1..b4466b31d7c8 100644
--- a/arch/arm64/kvm/pkvm.c
+++ b/arch/arm64/kvm/pkvm.c
@@ -6,6 +6,7 @@
#include <linux/kvm_host.h>
#include <linux/memblock.h>
+#include <linux/mutex.h>
#include <linux/sort.h>
#include <asm/kvm_pkvm.h>
@@ -94,3 +95,114 @@ void __init kvm_hyp_reserve(void)
kvm_info("Reserved %lld MiB at 0x%llx\n", hyp_mem_size >> 20,
hyp_mem_base);
}
+
+/*
+ * Allocates and donates memory for EL2 shadow structs.
+ *
+ * Allocates space for the shadow state, which includes the shadow vm as well as
+ * the shadow vcpu states.
+ *
+ * Stores an opaque handler in the kvm struct for future reference.
+ *
+ * Return 0 on success, negative error code on failure.
+ */
+static int __kvm_shadow_create(struct kvm *kvm)
+{
+ struct kvm_vcpu *vcpu, **vcpu_array;
+ unsigned int shadow_handle;
+ size_t pgd_sz, shadow_sz;
+ void *pgd, *shadow_addr;
+ unsigned long idx;
+ int ret;
+
+ if (kvm->created_vcpus < 1)
+ return -EINVAL;
+
+ pgd_sz = kvm_pgtable_stage2_pgd_size(kvm->arch.vtcr);
+ /*
+ * The PGD pages will be reclaimed using a hyp_memcache which implies
+ * page granularity. So, use alloc_pages_exact() to get individual
+ * refcounts.
+ */
+ pgd = alloc_pages_exact(pgd_sz, GFP_KERNEL_ACCOUNT);
+ if (!pgd)
+ return -ENOMEM;
+
+ /* Allocate memory to donate to hyp for the kvm and vcpu state. */
+ shadow_sz = PAGE_ALIGN(KVM_SHADOW_VM_SIZE +
+ KVM_SHADOW_VCPU_STATE_SIZE * kvm->created_vcpus);
+ shadow_addr = alloc_pages_exact(shadow_sz, GFP_KERNEL_ACCOUNT);
+ if (!shadow_addr) {
+ ret = -ENOMEM;
+ goto free_pgd;
+ }
+
+ /* Stash the vcpu pointers into the PGD */
+ BUILD_BUG_ON(KVM_MAX_VCPUS > (PAGE_SIZE / sizeof(u64)));
+ vcpu_array = pgd;
+ kvm_for_each_vcpu(idx, vcpu, kvm) {
+ /* Indexing of the vcpus to be sequential starting at 0. */
+ if (WARN_ON(vcpu->vcpu_idx != idx)) {
+ ret = -EINVAL;
+ goto free_shadow;
+ }
+
+ vcpu_array[idx] = vcpu;
+ }
+
+ /* Donate the shadow memory to hyp and let hyp initialize it. */
+ ret = kvm_call_hyp_nvhe(__pkvm_init_shadow, kvm, shadow_addr, shadow_sz,
+ pgd);
+ if (ret < 0)
+ goto free_shadow;
+
+ shadow_handle = ret;
+
+ /* Store the shadow handle given by hyp for future call reference. */
+ kvm->arch.pkvm.shadow_handle = shadow_handle;
+ kvm->arch.pkvm.hyp_donations.pgd = pgd;
+ kvm->arch.pkvm.hyp_donations.shadow = shadow_addr;
+ return 0;
+
+free_shadow:
+ free_pages_exact(shadow_addr, shadow_sz);
+free_pgd:
+ free_pages_exact(pgd, pgd_sz);
+ return ret;
+}
+
+int kvm_shadow_create(struct kvm *kvm)
+{
+ int ret = 0;
+
+ mutex_lock(&kvm->arch.pkvm.shadow_lock);
+ if (!kvm->arch.pkvm.shadow_handle)
+ ret = __kvm_shadow_create(kvm);
+ mutex_unlock(&kvm->arch.pkvm.shadow_lock);
+
+ return ret;
+}
+
+void kvm_shadow_destroy(struct kvm *kvm)
+{
+ size_t pgd_sz, shadow_sz;
+
+ if (kvm->arch.pkvm.shadow_handle)
+ WARN_ON(kvm_call_hyp_nvhe(__pkvm_teardown_shadow,
+ kvm->arch.pkvm.shadow_handle));
+
+ kvm->arch.pkvm.shadow_handle = 0;
+
+ shadow_sz = PAGE_ALIGN(KVM_SHADOW_VM_SIZE +
+ KVM_SHADOW_VCPU_STATE_SIZE * kvm->created_vcpus);
+ pgd_sz = kvm_pgtable_stage2_pgd_size(kvm->arch.vtcr);
+
+ free_pages_exact(kvm->arch.pkvm.hyp_donations.shadow, shadow_sz);
+ free_pages_exact(kvm->arch.pkvm.hyp_donations.pgd, pgd_sz);
+}
+
+int kvm_init_pvm(struct kvm *kvm)
+{
+ mutex_init(&kvm->arch.pkvm.shadow_lock);
+ return 0;
+}
--
2.37.0.rc0.161.g10f37bed90-goog
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