From patchwork Thu Jul 4 16:25:19 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thibault Ferrante X-Patchwork-Id: 1956971 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ubuntu.com (client-ip=185.125.189.65; helo=lists.ubuntu.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=patchwork.ozlabs.org) Received: from lists.ubuntu.com (lists.ubuntu.com [185.125.189.65]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4WFMT51Vk5z1xpP for ; Fri, 5 Jul 2024 02:25:45 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=lists.ubuntu.com) by lists.ubuntu.com with esmtp (Exim 4.86_2) (envelope-from ) id 1sPPH9-0001iH-Gn; Thu, 04 Jul 2024 16:25:39 +0000 Received: from smtp-relay-canonical-0.internal ([10.131.114.83] helo=smtp-relay-canonical-0.canonical.com) by lists.ubuntu.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1sPPH7-0001h1-TC for kernel-team@lists.ubuntu.com; Thu, 04 Jul 2024 16:25:37 +0000 Received: from Q58-sff.. (2.general.thibf.uk.vpn [10.172.200.120]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-canonical-0.canonical.com (Postfix) with ESMTPSA id 42DF83F2E1; Thu, 4 Jul 2024 16:25:37 +0000 (UTC) From: Thibault Ferrante To: kernel-team@lists.ubuntu.com Subject: [SRU][N:intel][PATCH 2/4] KVM: selftests: Allow tagging protected memory in guest page tables Date: Thu, 4 Jul 2024 18:25:19 +0200 Message-ID: <20240704162521.3375266-3-thibault.ferrante@canonical.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240704162521.3375266-1-thibault.ferrante@canonical.com> References: <20240704162521.3375266-1-thibault.ferrante@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Peter Gonda BugLink: https://bugs.launchpad.net/bugs/2071628 Add support for tagging and untagging guest physical address, e.g. to allow x86's SEV and TDX guests to embed shared vs. private information in the GPA. SEV (encryption, a.k.a. C-bit) and TDX (shared, a.k.a. S-bit) steal bits from the guest's physical address space that is consumed by the CPU metadata, i.e. effectively aliases the "real" GPA. Implement generic "tagging" so that the shared vs. private metadata can be managed by x86 without bleeding too many details into common code. Cc: Paolo Bonzini Cc: Sean Christopherson Cc: Vishal Annapurve Cc: Ackerly Tng cc: Andrew Jones Cc: Tom Lendacky Cc: Michael Roth Tested-by: Carlos Bilbao Originally-by: Michael Roth Signed-off-by: Peter Gonda Link: https://lore.kernel.org/r/20240223004258.3104051-8-seanjc@google.com Signed-off-by: Sean Christopherson (cherry picked from commit be1bd4c5394ff7eb6f14aaf8005824ed1946bb82) Signed-off-by: Thibault Ferrante --- .../kvm/include/aarch64/kvm_util_arch.h | 7 +++++++ .../selftests/kvm/include/kvm_util_base.h | 13 ++++++++++++ .../kvm/include/riscv/kvm_util_arch.h | 7 +++++++ .../kvm/include/s390x/kvm_util_arch.h | 7 +++++++ .../kvm/include/x86_64/kvm_util_arch.h | 21 +++++++++++++++++++ tools/testing/selftests/kvm/lib/kvm_util.c | 17 +++++++++++++++ .../selftests/kvm/lib/x86_64/processor.c | 15 ++++++++++++- 7 files changed, 86 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/kvm/include/aarch64/kvm_util_arch.h create mode 100644 tools/testing/selftests/kvm/include/riscv/kvm_util_arch.h create mode 100644 tools/testing/selftests/kvm/include/s390x/kvm_util_arch.h create mode 100644 tools/testing/selftests/kvm/include/x86_64/kvm_util_arch.h diff --git a/tools/testing/selftests/kvm/include/aarch64/kvm_util_arch.h b/tools/testing/selftests/kvm/include/aarch64/kvm_util_arch.h new file mode 100644 index 000000000000..e43a57d99b56 --- /dev/null +++ b/tools/testing/selftests/kvm/include/aarch64/kvm_util_arch.h @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef SELFTEST_KVM_UTIL_ARCH_H +#define SELFTEST_KVM_UTIL_ARCH_H + +struct kvm_vm_arch {}; + +#endif // SELFTEST_KVM_UTIL_ARCH_H diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h index 9e5afc472c14..c77ee35c551d 100644 --- a/tools/testing/selftests/kvm/include/kvm_util_base.h +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h @@ -18,9 +18,11 @@ #include #include +#include #include +#include "kvm_util_arch.h" #include "sparsebit.h" /* @@ -111,6 +113,9 @@ struct kvm_vm { vm_vaddr_t idt; vm_vaddr_t handlers; uint32_t dirty_ring_size; + uint64_t gpa_tag_mask; + + struct kvm_vm_arch arch; /* Cache of information for binary stats interface */ int stats_fd; @@ -585,6 +590,12 @@ void *addr_gva2hva(struct kvm_vm *vm, vm_vaddr_t gva); vm_paddr_t addr_hva2gpa(struct kvm_vm *vm, void *hva); void *addr_gpa2alias(struct kvm_vm *vm, vm_paddr_t gpa); + +static inline vm_paddr_t vm_untag_gpa(struct kvm_vm *vm, vm_paddr_t gpa) +{ + return gpa & ~vm->gpa_tag_mask; +} + void vcpu_run(struct kvm_vcpu *vcpu); int _vcpu_run(struct kvm_vcpu *vcpu); @@ -1081,4 +1092,6 @@ void kvm_selftest_arch_init(void); void kvm_arch_vm_post_create(struct kvm_vm *vm); +bool vm_is_gpa_protected(struct kvm_vm *vm, vm_paddr_t paddr); + #endif /* SELFTEST_KVM_UTIL_BASE_H */ diff --git a/tools/testing/selftests/kvm/include/riscv/kvm_util_arch.h b/tools/testing/selftests/kvm/include/riscv/kvm_util_arch.h new file mode 100644 index 000000000000..e43a57d99b56 --- /dev/null +++ b/tools/testing/selftests/kvm/include/riscv/kvm_util_arch.h @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef SELFTEST_KVM_UTIL_ARCH_H +#define SELFTEST_KVM_UTIL_ARCH_H + +struct kvm_vm_arch {}; + +#endif // SELFTEST_KVM_UTIL_ARCH_H diff --git a/tools/testing/selftests/kvm/include/s390x/kvm_util_arch.h b/tools/testing/selftests/kvm/include/s390x/kvm_util_arch.h new file mode 100644 index 000000000000..e43a57d99b56 --- /dev/null +++ b/tools/testing/selftests/kvm/include/s390x/kvm_util_arch.h @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef SELFTEST_KVM_UTIL_ARCH_H +#define SELFTEST_KVM_UTIL_ARCH_H + +struct kvm_vm_arch {}; + +#endif // SELFTEST_KVM_UTIL_ARCH_H diff --git a/tools/testing/selftests/kvm/include/x86_64/kvm_util_arch.h b/tools/testing/selftests/kvm/include/x86_64/kvm_util_arch.h new file mode 100644 index 000000000000..cfdf8c5e2671 --- /dev/null +++ b/tools/testing/selftests/kvm/include/x86_64/kvm_util_arch.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef SELFTEST_KVM_UTIL_ARCH_H +#define SELFTEST_KVM_UTIL_ARCH_H + +#include +#include + +struct kvm_vm_arch { + uint64_t c_bit; + uint64_t s_bit; +}; + +static inline bool __vm_arch_has_protected_memory(struct kvm_vm_arch *arch) +{ + return arch->c_bit || arch->s_bit; +} + +#define vm_arch_has_protected_memory(vm) \ + __vm_arch_has_protected_memory(&(vm)->arch) + +#endif // SELFTEST_KVM_UTIL_ARCH_H diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 1b197426f29f..b9a82242f947 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -1527,6 +1527,8 @@ void *addr_gpa2hva(struct kvm_vm *vm, vm_paddr_t gpa) { struct userspace_mem_region *region; + gpa = vm_untag_gpa(vm, gpa); + region = userspace_mem_region_find(vm, gpa, gpa); if (!region) { TEST_FAIL("No vm physical memory at 0x%lx", gpa); @@ -2224,3 +2226,18 @@ void __attribute((constructor)) kvm_selftest_init(void) kvm_selftest_arch_init(); } + +bool vm_is_gpa_protected(struct kvm_vm *vm, vm_paddr_t paddr) +{ + sparsebit_idx_t pg = 0; + struct userspace_mem_region *region; + + if (!vm_arch_has_protected_memory(vm)) + return false; + + region = userspace_mem_region_find(vm, paddr, paddr); + TEST_ASSERT(region, "No vm physical memory at 0x%lx", paddr); + + pg = paddr >> vm->page_shift; + return sparsebit_is_set(region->protected_phy_pages, pg); +} diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index f639b3e062e3..609f342cadf6 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -157,6 +157,8 @@ static uint64_t *virt_create_upper_pte(struct kvm_vm *vm, { uint64_t *pte = virt_get_pte(vm, parent_pte, vaddr, current_level); + paddr = vm_untag_gpa(vm, paddr); + if (!(*pte & PTE_PRESENT_MASK)) { *pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK; if (current_level == target_level) @@ -200,6 +202,8 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level) "Physical address beyond maximum supported,\n" " paddr: 0x%lx vm->max_gfn: 0x%lx vm->page_size: 0x%x", paddr, vm->max_gfn, vm->page_size); + TEST_ASSERT(vm_untag_gpa(vm, paddr) == paddr, + "Unexpected bits in paddr: %lx", paddr); /* * Allocate upper level page tables, if not already present. Return @@ -222,6 +226,15 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level) TEST_ASSERT(!(*pte & PTE_PRESENT_MASK), "PTE already present for 4k page at vaddr: 0x%lx", vaddr); *pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK | (paddr & PHYSICAL_PAGE_MASK); + + /* + * Neither SEV nor TDX supports shared page tables, so only the final + * leaf PTE needs manually set the C/S-bit. + */ + if (vm_is_gpa_protected(vm, paddr)) + *pte |= vm->arch.c_bit; + else + *pte |= vm->arch.s_bit; } void virt_arch_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr) @@ -496,7 +509,7 @@ vm_paddr_t addr_arch_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva) * No need for a hugepage mask on the PTE, x86-64 requires the "unused" * address bits to be zero. */ - return PTE_GET_PA(*pte) | (gva & ~HUGEPAGE_MASK(level)); + return vm_untag_gpa(vm, PTE_GET_PA(*pte)) | (gva & ~HUGEPAGE_MASK(level)); } static void kvm_setup_gdt(struct kvm_vm *vm, struct kvm_dtable *dt)