On 12/12/2023 12:47 PM, Sagi Shahar wrote:

-----Original Message----- From: Sagi Shahar sagis@google.com Sent: Tuesday, December 12, 2023 12:47 PM To: linux-kselftest@vger.kernel.org; Ackerley Tng ackerleytng@google.com; Afranji, Ryan afranji@google.com; Aktas, Erdem erdemaktas@google.com; Sagi Shahar sagis@google.com; Yamahata, Isaku isaku.yamahata@intel.com Cc: Sean Christopherson seanjc@google.com; Paolo Bonzini pbonzini@redhat.com; Shuah Khan shuah@kernel.org; Peter Gonda pgonda@google.com; Xu, Haibo1 haibo1.xu@intel.com; Chao Peng chao.p.peng@linux.intel.com; Annapurve, Vishal vannapurve@google.com; Roger Wang runanwang@google.com; Vipin Sharma vipinsh@google.com; jmattson@google.com; dmatlack@google.com; linux-kernel@vger.kernel.org; kvm@vger.kernel.org; linux-mm@kvack.org Subject: [RFC PATCH v5 22/29] KVM: selftests: Add functions to allow mapping as shared

Since protected_phy_pages is introduced to keep track of the guest memory's private/shared property, it's better to keep it consistent with the guest mappings.

Instead of having a set of new APIs to force it to map shared guest pages, how about to update protected_phy_pages sparsebits right before the mapping, and just call the existing virt_pg_map() to do the mapping?

From: Ackerley Tng ackerleytng@google.com

Signed-off-by: Ackerley Tng ackerleytng@google.com Signed-off-by: Ryan Afranji afranji@google.com Signed-off-by: Sagi Shahar sagis@google.com

---

.../selftests/kvm/include/kvm_util_base.h | 24 ++++++++++++++ tools/testing/selftests/kvm/lib/kvm_util.c | 32 +++++++++++++++++++ .../selftests/kvm/lib/x86_64/processor.c | 15 +++++++-- 3 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h index b353617fcdd1..efd7ae8abb20 100644 --- a/tools/testing/selftests/kvm/include/kvm_util_base.h +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h @@ -574,6 +574,8 @@ vm_vaddr_t vm_vaddr_alloc_page(struct kvm_vm *vm); void virt_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, unsigned int npages); +void virt_map_shared(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,

•      unsigned int npages);
  

void *addr_gpa2hva(struct kvm_vm *vm, vm_paddr_t gpa); void *addr_gva2hva(struct kvm_vm *vm, vm_vaddr_t gva); vm_paddr_t addr_hva2gpa(struct kvm_vm *vm, void *hva); @@ -1034,6 +1036,28 @@ static inline void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr virt_arch_pg_map(vm, vaddr, paddr); } +/*

• • VM Virtual Page Map as Shared
• • Input Args:
• • vm - Virtual Machine
• • vaddr - VM Virtual Address
• • paddr - VM Physical Address
• • memslot - Memory region slot for new virtual translation tables
• • Output Args: None
• • Return: None
• • Within @vm, creates a virtual translation for the page starting
• • at @vaddr to the page starting at @paddr.
• */

+void virt_arch_pg_map_shared(struct kvm_vm *vm, uint64_t vaddr, +uint64_t paddr);

+static inline void virt_pg_map_shared(struct kvm_vm *vm, uint64_t +vaddr, uint64_t paddr) {

• virt_arch_pg_map_shared(vm, vaddr, paddr); }

/*

• Address Guest Virtual to Guest Physical diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c

index 4f1ae0f1eef0..28780fa1f0f2 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -1573,6 +1573,38 @@ void virt_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, } } +/*

• • Map a range of VM virtual address to the VM's physical address as

+shared

• • Input Args:
• • vm - Virtual Machine
• • vaddr - Virtuall address to map
• • paddr - VM Physical Address
• • npages - The number of pages to map
• • Output Args: None
• • Return: None
• • Within the VM given by @vm, creates a virtual translation for
• • @npages starting at @vaddr to the page range starting at @paddr.
• */

+void virt_map_shared(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,

•      unsigned int npages)
  

+{

• size_t page_size = vm->page_size;
• size_t size = npages * page_size;
• TEST_ASSERT(vaddr + size > vaddr, "Vaddr overflow");
• TEST_ASSERT(paddr + size > paddr, "Paddr overflow");
• while (npages--) {

• virt_pg_map_shared(vm, vaddr, paddr);
  

• vaddr += page_size;
  

• paddr += page_size;
  

• }

+}

/*

• Address VM Physical to Host Virtual

diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index 566d82829da4..aa2a57ddb8d3 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -190,7 +190,8 @@ static uint64_t *virt_create_upper_pte(struct kvm_vm *vm, return pte; } -void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level) +static void ___virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,

• 	   int level, bool protected)
  

{ const uint64_t pg_size = PG_LEVEL_SIZE(level); uint64_t *pml4e, *pdpe, *pde; @@ -235,17 +236,27 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level) "PTE already present for 4k page at vaddr: 0x%lx\n", vaddr); *pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK | (paddr & PHYSICAL_PAGE_MASK);

• if (vm_is_gpa_protected(vm, paddr))

• if (protected)> *pte |= vm->arch.c_bit; else *pte |= vm->arch.s_bit;

} +void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, +int level) {

• ___virt_pg_map(vm, vaddr, paddr, level, vm_is_gpa_protected(vm,

+paddr)); }

void virt_arch_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr) { __virt_pg_map(vm, vaddr, paddr, PG_LEVEL_4K); } +void virt_arch_pg_map_shared(struct kvm_vm *vm, uint64_t vaddr, +uint64_t paddr) {

• ___virt_pg_map(vm, vaddr, paddr, PG_LEVEL_4K, false); }

Here, it tries to create the guest mappings regardless of what the value of protected_phy_pages is, which could create confusion.

void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, uint64_t nr_bytes, int level) { -- 2.43.0.472.g3155946c3a-goog