From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
Marc Zyngier <maz@kernel.org>, Oliver Upton <oupton@kernel.org>,
Tianrui Zhao <zhaotianrui@loongson.cn>,
Bibo Mao <maobibo@loongson.cn>,
Huacai Chen <chenhuacai@kernel.org>,
Anup Patel <anup@brainfault.org>, Paul Walmsley <pjw@kernel.org>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Janosch Frank <frankja@linux.ibm.com>,
Claudio Imbrenda <imbrenda@linux.ibm.com>,
Sean Christopherson <seanjc@google.com>
Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
kvmarm@lists.linux.dev, loongarch@lists.linux.dev,
kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org,
linux-kernel@vger.kernel.org,
Yosry Ahmed <yosry.ahmed@linux.dev>
Subject: [PATCH v4 16/21] KVM: selftests: Add support for nested NPTs
Date: Tue, 30 Dec 2025 15:01:45 -0800 [thread overview]
Message-ID: <20251230230150.4150236-17-seanjc@google.com> (raw)
In-Reply-To: <20251230230150.4150236-1-seanjc@google.com>
From: Yosry Ahmed <yosry.ahmed@linux.dev>
Implement nCR3 and NPT initialization functions, similar to the EPT
equivalents, and create common TDP helpers for enablement checking and
initialization. Enable NPT for nested guests by default if the TDP MMU
was initialized, similar to VMX.
Reuse the PTE masks from the main MMU in the NPT MMU, except for the C
and S bits related to confidential VMs.
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
.../selftests/kvm/include/x86/processor.h | 2 ++
.../selftests/kvm/include/x86/svm_util.h | 9 ++++++++
.../testing/selftests/kvm/lib/x86/memstress.c | 4 ++--
.../testing/selftests/kvm/lib/x86/processor.c | 15 +++++++++++++
tools/testing/selftests/kvm/lib/x86/svm.c | 21 +++++++++++++++++++
.../selftests/kvm/x86/vmx_dirty_log_test.c | 4 ++--
6 files changed, 51 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/testing/selftests/kvm/include/x86/processor.h
index d134c886f280..deb471fb9b51 100644
--- a/tools/testing/selftests/kvm/include/x86/processor.h
+++ b/tools/testing/selftests/kvm/include/x86/processor.h
@@ -1477,6 +1477,8 @@ void __virt_pg_map(struct kvm_vm *vm, struct kvm_mmu *mmu, uint64_t vaddr,
void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
uint64_t nr_bytes, int level);
+void vm_enable_tdp(struct kvm_vm *vm);
+bool kvm_cpu_has_tdp(void);
void tdp_map(struct kvm_vm *vm, uint64_t nested_paddr, uint64_t paddr, uint64_t size);
void tdp_identity_map_default_memslots(struct kvm_vm *vm);
void tdp_identity_map_1g(struct kvm_vm *vm, uint64_t addr, uint64_t size);
diff --git a/tools/testing/selftests/kvm/include/x86/svm_util.h b/tools/testing/selftests/kvm/include/x86/svm_util.h
index b74c6dcddcbd..5d7c42534bc4 100644
--- a/tools/testing/selftests/kvm/include/x86/svm_util.h
+++ b/tools/testing/selftests/kvm/include/x86/svm_util.h
@@ -27,6 +27,9 @@ struct svm_test_data {
void *msr; /* gva */
void *msr_hva;
uint64_t msr_gpa;
+
+ /* NPT */
+ uint64_t ncr3_gpa;
};
static inline void vmmcall(void)
@@ -57,6 +60,12 @@ struct svm_test_data *vcpu_alloc_svm(struct kvm_vm *vm, vm_vaddr_t *p_svm_gva);
void generic_svm_setup(struct svm_test_data *svm, void *guest_rip, void *guest_rsp);
void run_guest(struct vmcb *vmcb, uint64_t vmcb_gpa);
+static inline bool kvm_cpu_has_npt(void)
+{
+ return kvm_cpu_has(X86_FEATURE_NPT);
+}
+void vm_enable_npt(struct kvm_vm *vm);
+
int open_sev_dev_path_or_exit(void);
#endif /* SELFTEST_KVM_SVM_UTILS_H */
diff --git a/tools/testing/selftests/kvm/lib/x86/memstress.c b/tools/testing/selftests/kvm/lib/x86/memstress.c
index 3319cb57a78d..407abfc34909 100644
--- a/tools/testing/selftests/kvm/lib/x86/memstress.c
+++ b/tools/testing/selftests/kvm/lib/x86/memstress.c
@@ -82,9 +82,9 @@ void memstress_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_vcpu *vc
int vcpu_id;
TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));
- TEST_REQUIRE(kvm_cpu_has_ept());
+ TEST_REQUIRE(kvm_cpu_has_tdp());
- vm_enable_ept(vm);
+ vm_enable_tdp(vm);
for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
vcpu_alloc_vmx(vm, &vmx_gva);
diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index 29e7d172f945..a3a4c9a4cbcb 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -8,7 +8,9 @@
#include "kvm_util.h"
#include "pmu.h"
#include "processor.h"
+#include "svm_util.h"
#include "sev.h"
+#include "vmx.h"
#ifndef NUM_INTERRUPTS
#define NUM_INTERRUPTS 256
@@ -472,6 +474,19 @@ void virt_arch_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent)
}
}
+void vm_enable_tdp(struct kvm_vm *vm)
+{
+ if (kvm_cpu_has(X86_FEATURE_VMX))
+ vm_enable_ept(vm);
+ else
+ vm_enable_npt(vm);
+}
+
+bool kvm_cpu_has_tdp(void)
+{
+ return kvm_cpu_has_ept() || kvm_cpu_has_npt();
+}
+
void __tdp_map(struct kvm_vm *vm, uint64_t nested_paddr, uint64_t paddr,
uint64_t size, int level)
{
diff --git a/tools/testing/selftests/kvm/lib/x86/svm.c b/tools/testing/selftests/kvm/lib/x86/svm.c
index d239c2097391..8e4795225595 100644
--- a/tools/testing/selftests/kvm/lib/x86/svm.c
+++ b/tools/testing/selftests/kvm/lib/x86/svm.c
@@ -59,6 +59,22 @@ static void vmcb_set_seg(struct vmcb_seg *seg, u16 selector,
seg->base = base;
}
+void vm_enable_npt(struct kvm_vm *vm)
+{
+ struct pte_masks pte_masks;
+
+ TEST_ASSERT(kvm_cpu_has_npt(), "KVM doesn't supported nested NPT");
+
+ /*
+ * NPTs use the same PTE format, but deliberately drop the C-bit as the
+ * per-VM shared vs. private information is only meant for stage-1.
+ */
+ pte_masks = vm->mmu.arch.pte_masks;
+ pte_masks.c = 0;
+
+ tdp_mmu_init(vm, vm->mmu.pgtable_levels, &pte_masks);
+}
+
void generic_svm_setup(struct svm_test_data *svm, void *guest_rip, void *guest_rsp)
{
struct vmcb *vmcb = svm->vmcb;
@@ -102,6 +118,11 @@ void generic_svm_setup(struct svm_test_data *svm, void *guest_rip, void *guest_r
vmcb->save.rip = (u64)guest_rip;
vmcb->save.rsp = (u64)guest_rsp;
guest_regs.rdi = (u64)svm;
+
+ if (svm->ncr3_gpa) {
+ ctrl->nested_ctl |= SVM_NESTED_CTL_NP_ENABLE;
+ ctrl->nested_cr3 = svm->ncr3_gpa;
+ }
}
/*
diff --git a/tools/testing/selftests/kvm/x86/vmx_dirty_log_test.c b/tools/testing/selftests/kvm/x86/vmx_dirty_log_test.c
index 370f8d3117c2..032ab8bf60a4 100644
--- a/tools/testing/selftests/kvm/x86/vmx_dirty_log_test.c
+++ b/tools/testing/selftests/kvm/x86/vmx_dirty_log_test.c
@@ -93,7 +93,7 @@ static void test_vmx_dirty_log(bool enable_ept)
/* Create VM */
vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code);
if (enable_ept)
- vm_enable_ept(vm);
+ vm_enable_tdp(vm);
vcpu_alloc_vmx(vm, &vmx_pages_gva);
vcpu_args_set(vcpu, 1, vmx_pages_gva);
@@ -170,7 +170,7 @@ int main(int argc, char *argv[])
test_vmx_dirty_log(/*enable_ept=*/false);
- if (kvm_cpu_has_ept())
+ if (kvm_cpu_has_tdp())
test_vmx_dirty_log(/*enable_ept=*/true);
return 0;
--
2.52.0.351.gbe84eed79e-goog
next prev parent reply other threads:[~2025-12-30 23:04 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-30 23:01 [PATCH v4 00/21] KVM: selftests: Add Nested NPT support Sean Christopherson
2025-12-30 23:01 ` [PATCH v4 01/21] KVM: selftests: Make __vm_get_page_table_entry() static Sean Christopherson
2025-12-30 23:01 ` [PATCH v4 02/21] KVM: selftests: Stop passing a memslot to nested_map_memslot() Sean Christopherson
2025-12-30 23:01 ` [PATCH v4 03/21] KVM: selftests: Rename nested TDP mapping functions Sean Christopherson
2025-12-30 23:01 ` [PATCH v4 04/21] KVM: selftests: Kill eptPageTablePointer Sean Christopherson
2025-12-30 23:01 ` [PATCH v4 05/21] KVM: selftests: Stop setting A/D bits when creating EPT PTEs Sean Christopherson
2025-12-30 23:01 ` [PATCH v4 06/21] KVM: selftests: Add "struct kvm_mmu" to track a given MMU instance Sean Christopherson
2026-01-02 16:50 ` Yosry Ahmed
2025-12-30 23:01 ` [PATCH v4 07/21] KVM: selftests: Plumb "struct kvm_mmu" into x86's MMU APIs Sean Christopherson
2025-12-30 23:01 ` [PATCH v4 08/21] KVM: selftests: Add a "struct kvm_mmu_arch arch" member to kvm_mmu Sean Christopherson
2026-01-02 16:53 ` Yosry Ahmed
2026-01-02 17:02 ` Yosry Ahmed
2025-12-30 23:01 ` [PATCH v4 09/21] KVM: selftests: Move PTE bitmasks " Sean Christopherson
2025-12-30 23:01 ` [PATCH v4 10/21] KVM: selftests: Use a TDP MMU to share EPT page tables between vCPUs Sean Christopherson
2025-12-30 23:01 ` [PATCH v4 11/21] KVM: selftests: Stop passing VMX metadata to TDP mapping functions Sean Christopherson
2026-01-02 16:58 ` Yosry Ahmed
2026-01-02 17:12 ` Yosry Ahmed
2025-12-30 23:01 ` [PATCH v4 12/21] KVM: selftests: Add a stage-2 MMU instance to kvm_vm Sean Christopherson
2026-01-02 17:03 ` Yosry Ahmed
2025-12-30 23:01 ` [PATCH v4 13/21] KVM: selftests: Reuse virt mapping functions for nested EPTs Sean Christopherson
2025-12-30 23:01 ` [PATCH v4 14/21] KVM: selftests: Move TDP mapping functions outside of vmx.c Sean Christopherson
2025-12-30 23:01 ` [PATCH v4 15/21] KVM: selftests: Allow kvm_cpu_has_ept() to be called on AMD CPUs Sean Christopherson
2025-12-30 23:01 ` Sean Christopherson [this message]
2026-01-07 23:12 ` [PATCH v4 16/21] KVM: selftests: Add support for nested NPTs Yosry Ahmed
2025-12-30 23:01 ` [PATCH v4 17/21] KVM: selftests: Set the user bit on nested NPT PTEs Sean Christopherson
2025-12-30 23:01 ` [PATCH v4 18/21] KVM: selftests: Extend vmx_dirty_log_test to cover SVM Sean Christopherson
2025-12-30 23:01 ` [PATCH v4 19/21] KVM: selftests: Extend memstress to run on nested SVM Sean Christopherson
2025-12-30 23:01 ` [PATCH v4 20/21] KVM: selftests: Rename vm_get_page_table_entry() to vm_get_pte() Sean Christopherson
2026-01-02 17:10 ` Yosry Ahmed
2025-12-30 23:01 ` [PATCH v4 21/21] KVM: selftests: Test READ=>WRITE dirty logging behavior for shadow MMU Sean Christopherson
2026-01-02 17:36 ` Yosry Ahmed
2026-01-08 16:32 ` Sean Christopherson
2026-01-08 18:01 ` Yosry Ahmed
2026-01-08 18:31 ` Sean Christopherson
2026-01-08 20:24 ` Yosry Ahmed
2026-01-08 20:29 ` Sean Christopherson
2026-01-08 20:33 ` Yosry Ahmed
2026-01-08 20:26 ` Yosry Ahmed
2026-01-12 17:38 ` [PATCH v4 00/21] KVM: selftests: Add Nested NPT support Sean Christopherson
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