mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-10-04 08:08:54 +00:00
Code Issues Releases Wiki Activity

KVM: selftests: Fix nx_huge_pages_test on TDP-disabled hosts

Browse source 
Map the test's huge page region with 2MiB virtual mappings when TDP is
disabled so that KVM can shadow the region with huge pages. This fixes
nx_huge_pages_test on hosts where TDP hardware support is disabled.

Purposely do not skip this test on TDP-disabled hosts. While we don't
care about NX Huge Pages on TDP-disabled hosts from a security
perspective, KVM does support it, and so we should test it.

For TDP-enabled hosts, continue mapping the region with 4KiB pages to
ensure that KVM can map it with huge pages irrespective of the guest
mappings.

Fixes: 8448ec5993 ("KVM: selftests: Add NX huge pages test")
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20220929181207.2281449-4-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
David Matlack 2022-09-29 11:12:07 -07:00 committed by Paolo Bonzini
parent 4d2bd14319
commit 458e98746f
3 changed files with 48 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
tools/testing/selftests/kvm/include/x86_64/processor.h
View file

@ -825,6 +825,8 @@ static inline uint8_t wrmsr_safe(uint32_t msr, uint64_t val)
return kvm_asm_safe("wrmsr", "a"(val & -1u), "d"(val >> 32), "c"(msr));
}
bool kvm_is_tdp_enabled(void);
uint64_t vm_get_page_table_entry(struct kvm_vm *vm, struct kvm_vcpu *vcpu,
uint64_t vaddr);
void vm_set_page_table_entry(struct kvm_vm *vm, struct kvm_vcpu *vcpu,
@ -855,6 +857,8 @@ enum pg_level {
#define PG_SIZE_1G PG_LEVEL_SIZE(PG_LEVEL_1G)
void __virt_pg_map(struct kvm_vm *vm, 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);
/*
* Basic CPU control in CR0

27
tools/testing/selftests/kvm/lib/x86_64/processor.c
View file

@ -111,6 +111,14 @@ static void sregs_dump(FILE *stream, struct kvm_sregs *sregs, uint8_t indent)
}
}
bool kvm_is_tdp_enabled(void)
{
if (is_intel_cpu())
return get_kvm_intel_param_bool("ept");
else
return get_kvm_amd_param_bool("npt");
}
void virt_arch_pgd_alloc(struct kvm_vm *vm)
{
TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use "
@ -214,6 +222,25 @@ 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_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
uint64_t nr_bytes, int level)
{
uint64_t pg_size = PG_LEVEL_SIZE(level);
uint64_t nr_pages = nr_bytes / pg_size;
int i;
TEST_ASSERT(nr_bytes % pg_size == 0,
"Region size not aligned: nr_bytes: 0x%lx, page size: 0x%lx",
nr_bytes, pg_size);
for (i = 0; i < nr_pages; i++) {
__virt_pg_map(vm, vaddr, paddr, level);
vaddr += pg_size;
paddr += pg_size;
}
}
static uint64_t *_vm_get_page_table_entry(struct kvm_vm *vm,
struct kvm_vcpu *vcpu,
uint64_t vaddr)

19
tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c
View file

@ -112,6 +112,7 @@ void run_test(int reclaim_period_ms, bool disable_nx_huge_pages,
{
struct kvm_vcpu *vcpu;
struct kvm_vm *vm;
uint64_t nr_bytes;
void *hva;
int r;
@ -141,10 +142,24 @@ void run_test(int reclaim_period_ms, bool disable_nx_huge_pages,
HPAGE_GPA, HPAGE_SLOT,
HPAGE_SLOT_NPAGES, 0);
virt_map(vm, HPAGE_GVA, HPAGE_GPA, HPAGE_SLOT_NPAGES);
nr_bytes = HPAGE_SLOT_NPAGES * vm->page_size;
/*
* Ensure that KVM can map HPAGE_SLOT with huge pages by mapping the
* region into the guest with 2MiB pages whenever TDP is disabled (i.e.
* whenever KVM is shadowing the guest page tables).
*
* When TDP is enabled, KVM should be able to map HPAGE_SLOT with huge
* pages irrespective of the guest page size, so map with 4KiB pages
* to test that that is the case.
*/
if (kvm_is_tdp_enabled())
virt_map_level(vm, HPAGE_GVA, HPAGE_GPA, nr_bytes, PG_LEVEL_4K);
else
virt_map_level(vm, HPAGE_GVA, HPAGE_GPA, nr_bytes, PG_LEVEL_2M);
hva = addr_gpa2hva(vm, HPAGE_GPA);
memset(hva, RETURN_OPCODE, HPAGE_SLOT_NPAGES * PAGE_SIZE);
memset(hva, RETURN_OPCODE, nr_bytes);
check_2m_page_count(vm, 0);
check_split_count(vm, 0);