From nobody Mon Dec 1 22:31:40 2025 Received: from out-171.mta0.migadu.com (out-171.mta0.migadu.com [91.218.175.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BC74623F422 for ; Thu, 27 Nov 2025 01:35:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764207311; cv=none; b=Qam+9OlaQEVokY6U9RxZtluJisvSktAb79CmD8RCCehbxur4gby7+/KsfyO7BJxiSS8kk6z6Z6KqKidUghqjl9yZYUB2EkNlOv/RVMNaNDapoGQnQrLHLdqLnEW9mGcVZaXrhnlWu1zGmevH+CZOH6ozNF762UO5AKn5bO1Carc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764207311; c=relaxed/simple; bh=rJ8IoloP2mS8Aj9KDphh3mE3ooKXuct3r7Tjf9+L1aQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TAHlGp60VCatHsv6GC6+lu6SjTIOCUONq/sdeI3Oj5DfnEd7ARdYtnIptmJRiIXNBwkr8jQMOxIPLkm2o+t4QPeVAw4mCTSrzm9mg92QgFRmejgUeo9NsINC8SD/yKJDhah1pjSwnDsGtSWA6XNsOGnj5/tpXLgqx4DubWwR/5o= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=gGki0PWz; arc=none smtp.client-ip=91.218.175.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="gGki0PWz" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1764207307; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=b6AFu0tluctYDpxhADpmghqFz338Jgmap++Fi9r6Ggs=; b=gGki0PWztDUomJ33glUMRuprhXI+yoRhmi1BO77qhRd02vsnuafANITePQRUKOA5LMF2b4 mOxk+DlJRLdRnLVs+9ezIUYJDOGomkwbGKg4W4IASHZpl+M8YB9LIsUTRDUsMdTKMRGqrT L9prh8wa0DiFYV0nM0VyMDeEvuEG8Qk= From: Yosry Ahmed To: Sean Christopherson Cc: Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Yosry Ahmed Subject: [PATCH v3 06/16] KVM: selftests: Introduce struct kvm_mmu Date: Thu, 27 Nov 2025 01:34:30 +0000 Message-ID: <20251127013440.3324671-7-yosry.ahmed@linux.dev> In-Reply-To: <20251127013440.3324671-1-yosry.ahmed@linux.dev> References: <20251127013440.3324671-1-yosry.ahmed@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" In preparation for generalizing the virt mapping functions to work with TDP page tables, introduce struct kvm_mmu. This struct currently only holds the root GPA and number of page table levels. Parameterize virt mapping functions by the kvm_mmu, and use the root GPA and page table levels instead of hardcoding vm->pgd and vm->pgtable_levels. There's a subtle change here, instead of checking that the parent pointer is the address of the vm->pgd, check if the value pointed at by the parent pointer is the root GPA (i.e. the value of vm->pgd in this case). No change in behavior expected. Opportunistically, switch the ordering of the checks in the assertion in virt_get_pte(), as it makes more sense to check if the parent PTE is the root (in which case, not a PTE) before checking the present flag. vm->arch.mmu is dynamically allocated to avoid a circular dependency chain if kvm_util_arch.h includes processor.h for the struct definition: kvm_util_arch.h -> processor.h -> kvm_util.h -> kvm_util_arch.h No functional change intended. Suggested-by: Sean Christopherson Signed-off-by: Yosry Ahmed --- .../selftests/kvm/include/x86/kvm_util_arch.h | 4 ++ .../selftests/kvm/include/x86/processor.h | 8 ++- .../testing/selftests/kvm/lib/x86/processor.c | 61 +++++++++++++------ 3 files changed, 53 insertions(+), 20 deletions(-) diff --git a/tools/testing/selftests/kvm/include/x86/kvm_util_arch.h b/tool= s/testing/selftests/kvm/include/x86/kvm_util_arch.h index 972bb1c4ab4c..d8808fa33faa 100644 --- a/tools/testing/selftests/kvm/include/x86/kvm_util_arch.h +++ b/tools/testing/selftests/kvm/include/x86/kvm_util_arch.h @@ -10,6 +10,8 @@ =20 extern bool is_forced_emulation_enabled; =20 +struct kvm_mmu; + struct kvm_vm_arch { vm_vaddr_t gdt; vm_vaddr_t tss; @@ -19,6 +21,8 @@ struct kvm_vm_arch { uint64_t s_bit; int sev_fd; bool is_pt_protected; + + struct kvm_mmu *mmu; }; =20 static inline bool __vm_arch_has_protected_memory(struct kvm_vm_arch *arch) diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/te= sting/selftests/kvm/include/x86/processor.h index c00c0fbe62cd..0c295097c714 100644 --- a/tools/testing/selftests/kvm/include/x86/processor.h +++ b/tools/testing/selftests/kvm/include/x86/processor.h @@ -1449,7 +1449,13 @@ enum pg_level { #define PG_SIZE_2M PG_LEVEL_SIZE(PG_LEVEL_2M) #define PG_SIZE_1G PG_LEVEL_SIZE(PG_LEVEL_1G) =20 -void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int = level); +struct kvm_mmu { + uint64_t root_gpa; + int pgtable_levels; +}; + +void __virt_pg_map(struct kvm_vm *vm, struct kvm_mmu *mmu, uint64_t vaddr, + uint64_t paddr, int level); void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, uint64_t nr_bytes, int level); =20 diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testin= g/selftests/kvm/lib/x86/processor.c index c14bf2b5f28f..871de49c35ee 100644 --- a/tools/testing/selftests/kvm/lib/x86/processor.c +++ b/tools/testing/selftests/kvm/lib/x86/processor.c @@ -156,6 +156,23 @@ bool kvm_is_tdp_enabled(void) return get_kvm_amd_param_bool("npt"); } =20 +static struct kvm_mmu *mmu_create(struct kvm_vm *vm, + int pgtable_levels) +{ + struct kvm_mmu *mmu =3D calloc(1, sizeof(*mmu)); + + TEST_ASSERT(mmu, "-ENOMEM when allocating MMU"); + mmu->root_gpa =3D vm_alloc_page_table(vm); + mmu->pgtable_levels =3D pgtable_levels; + return mmu; +} + +static void mmu_init(struct kvm_vm *vm) +{ + vm->arch.mmu =3D mmu_create(vm, vm->pgtable_levels); + vm->pgd =3D vm->arch.mmu->root_gpa; +} + void virt_arch_pgd_alloc(struct kvm_vm *vm) { TEST_ASSERT(vm->mode =3D=3D VM_MODE_PXXVYY_4K, @@ -163,19 +180,19 @@ void virt_arch_pgd_alloc(struct kvm_vm *vm) =20 /* If needed, create the top-level page table. */ if (!vm->pgd_created) { - vm->pgd =3D vm_alloc_page_table(vm); + mmu_init(vm); vm->pgd_created =3D true; } } =20 -static void *virt_get_pte(struct kvm_vm *vm, uint64_t *parent_pte, - uint64_t vaddr, int level) +static void *virt_get_pte(struct kvm_vm *vm, struct kvm_mmu *mmu, + uint64_t *parent_pte, uint64_t vaddr, int level) { uint64_t pt_gpa =3D PTE_GET_PA(*parent_pte); uint64_t *page_table =3D addr_gpa2hva(vm, pt_gpa); int index =3D (vaddr >> PG_LEVEL_SHIFT(level)) & 0x1ffu; =20 - TEST_ASSERT((*parent_pte & PTE_PRESENT_MASK) || parent_pte =3D=3D &vm->pg= d, + TEST_ASSERT((*parent_pte =3D=3D mmu->root_gpa) || (*parent_pte & PTE_PRES= ENT_MASK), "Parent PTE (level %d) not PRESENT for gva: 0x%08lx", level + 1, vaddr); =20 @@ -183,13 +200,14 @@ static void *virt_get_pte(struct kvm_vm *vm, uint64_t= *parent_pte, } =20 static uint64_t *virt_create_upper_pte(struct kvm_vm *vm, + struct kvm_mmu *mmu, uint64_t *parent_pte, uint64_t vaddr, uint64_t paddr, int current_level, int target_level) { - uint64_t *pte =3D virt_get_pte(vm, parent_pte, vaddr, current_level); + uint64_t *pte =3D virt_get_pte(vm, mmu, parent_pte, vaddr, current_level); =20 paddr =3D vm_untag_gpa(vm, paddr); =20 @@ -215,10 +233,11 @@ static uint64_t *virt_create_upper_pte(struct kvm_vm = *vm, return pte; } =20 -void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int = level) +void __virt_pg_map(struct kvm_vm *vm, struct kvm_mmu *mmu, uint64_t vaddr, + uint64_t paddr, int level) { const uint64_t pg_size =3D PG_LEVEL_SIZE(level); - uint64_t *pte =3D &vm->pgd; + uint64_t *pte =3D &mmu->root_gpa; int current_level; =20 TEST_ASSERT(vm->mode =3D=3D VM_MODE_PXXVYY_4K, @@ -243,17 +262,17 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr,= uint64_t paddr, int level) * Allocate upper level page tables, if not already present. Return * early if a hugepage was created. */ - for (current_level =3D vm->pgtable_levels; + for (current_level =3D mmu->pgtable_levels; current_level > PG_LEVEL_4K; current_level--) { - pte =3D virt_create_upper_pte(vm, pte, vaddr, paddr, + pte =3D virt_create_upper_pte(vm, mmu, pte, vaddr, paddr, current_level, level); if (*pte & PTE_LARGE_MASK) return; } =20 /* Fill in page table entry. */ - pte =3D virt_get_pte(vm, pte, vaddr, PG_LEVEL_4K); + pte =3D virt_get_pte(vm, mmu, pte, vaddr, PG_LEVEL_4K); TEST_ASSERT(!(*pte & PTE_PRESENT_MASK), "PTE already present for 4k page at vaddr: 0x%lx", vaddr); *pte =3D PTE_PRESENT_MASK | PTE_WRITABLE_MASK | (paddr & PHYSICAL_PAGE_MA= SK); @@ -270,7 +289,7 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, u= int64_t paddr, int level) =20 void virt_arch_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr) { - __virt_pg_map(vm, vaddr, paddr, PG_LEVEL_4K); + __virt_pg_map(vm, vm->arch.mmu, vaddr, paddr, PG_LEVEL_4K); } =20 void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, @@ -285,7 +304,7 @@ void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, = uint64_t paddr, nr_bytes, pg_size); =20 for (i =3D 0; i < nr_pages; i++) { - __virt_pg_map(vm, vaddr, paddr, level); + __virt_pg_map(vm, vm->arch.mmu, vaddr, paddr, level); sparsebit_set_num(vm->vpages_mapped, vaddr >> vm->page_shift, nr_bytes / PAGE_SIZE); =20 @@ -294,7 +313,8 @@ void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, = uint64_t paddr, } } =20 -static bool vm_is_target_pte(uint64_t *pte, int *level, int current_level) +static bool vm_is_target_pte(struct kvm_mmu *mmu, uint64_t *pte, + int *level, int current_level) { if (*pte & PTE_LARGE_MASK) { TEST_ASSERT(*level =3D=3D PG_LEVEL_NONE || @@ -306,7 +326,9 @@ static bool vm_is_target_pte(uint64_t *pte, int *level,= int current_level) return *level =3D=3D current_level; } =20 -static uint64_t *__vm_get_page_table_entry(struct kvm_vm *vm, uint64_t vad= dr, +static uint64_t *__vm_get_page_table_entry(struct kvm_vm *vm, + struct kvm_mmu *mmu, + uint64_t vaddr, int *level) { int va_width =3D 12 + (vm->pgtable_levels) * 9; @@ -335,19 +357,19 @@ static uint64_t *__vm_get_page_table_entry(struct kvm= _vm *vm, uint64_t vaddr, for (current_level =3D vm->pgtable_levels; current_level > PG_LEVEL_4K; current_level--) { - pte =3D virt_get_pte(vm, pte, vaddr, current_level); - if (vm_is_target_pte(pte, level, current_level)) + pte =3D virt_get_pte(vm, mmu, pte, vaddr, current_level); + if (vm_is_target_pte(mmu, pte, level, current_level)) return pte; } =20 - return virt_get_pte(vm, pte, vaddr, PG_LEVEL_4K); + return virt_get_pte(vm, mmu, pte, vaddr, PG_LEVEL_4K); } =20 uint64_t *vm_get_page_table_entry(struct kvm_vm *vm, uint64_t vaddr) { int level =3D PG_LEVEL_4K; =20 - return __vm_get_page_table_entry(vm, vaddr, &level); + return __vm_get_page_table_entry(vm, vm->arch.mmu, vaddr, &level); } =20 void virt_arch_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent) @@ -497,7 +519,8 @@ static void kvm_seg_set_kernel_data_64bit(struct kvm_se= gment *segp) vm_paddr_t addr_arch_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva) { int level =3D PG_LEVEL_NONE; - uint64_t *pte =3D __vm_get_page_table_entry(vm, gva, &level); + struct kvm_mmu *mmu =3D vm->arch.mmu; + uint64_t *pte =3D __vm_get_page_table_entry(vm, mmu, gva, &level); =20 TEST_ASSERT(*pte & PTE_PRESENT_MASK, "Leaf PTE not PRESENT for gva: 0x%08lx", gva); --=20 2.52.0.158.g65b55ccf14-goog