On 21/03/20 06:05, Nadav Amit wrote:
> Running the tests with more than 4GB of memory results in the following
> failure:
>
> FAIL: EPT violation - paging structure
>
> It appears that the test mistakenly used get_ept_pte() to retrieve the
> guest PTE, but this function is intended for accessing EPT and not the
> guest page tables. Use get_pte_level() instead of get_ept_pte().
>
> Tested on bare-metal only.
>
> Signed-off-by: Nadav Amit <namit@xxxxxxxxxx>
> ---
> x86/vmx_tests.c | 17 +++++++++--------
> 1 file changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
> index be5c952..1f97fe3 100644
> --- a/x86/vmx_tests.c
> +++ b/x86/vmx_tests.c
> @@ -1312,12 +1312,14 @@ static int ept_exit_handler_common(union exit_reason exit_reason, bool have_ad)
> u64 guest_cr3;
> u32 insn_len;
> u32 exit_qual;
> - static unsigned long data_page1_pte, data_page1_pte_pte, memaddr_pte;
> + static unsigned long data_page1_pte, data_page1_pte_pte, memaddr_pte,
> + guest_pte_addr;
>
> guest_rip = vmcs_read(GUEST_RIP);
> guest_cr3 = vmcs_read(GUEST_CR3);
> insn_len = vmcs_read(EXI_INST_LEN);
> exit_qual = vmcs_read(EXI_QUALIFICATION);
> + pteval_t *ptep;
> switch (exit_reason.basic) {
> case VMX_VMCALL:
> switch (vmx_get_test_stage()) {
> @@ -1364,12 +1366,11 @@ static int ept_exit_handler_common(union exit_reason exit_reason, bool have_ad)
> ept_sync(INVEPT_SINGLE, eptp);
> break;
> case 4:
> - TEST_ASSERT(get_ept_pte(pml4, (unsigned long)data_page1,
> - 2, &data_page1_pte));
> - data_page1_pte &= PAGE_MASK;
> - TEST_ASSERT(get_ept_pte(pml4, data_page1_pte,
> - 2, &data_page1_pte_pte));
> - set_ept_pte(pml4, data_page1_pte, 2,
> + ptep = get_pte_level((pgd_t *)guest_cr3, data_page1, /*level=*/2);
> + guest_pte_addr = virt_to_phys(ptep) & PAGE_MASK;
> +
> + TEST_ASSERT(get_ept_pte(pml4, guest_pte_addr, 2, &data_page1_pte_pte));
> + set_ept_pte(pml4, guest_pte_addr, 2,
> data_page1_pte_pte & ~EPT_PRESENT);
> ept_sync(INVEPT_SINGLE, eptp);
> break;
> @@ -1437,7 +1438,7 @@ static int ept_exit_handler_common(union exit_reason exit_reason, bool have_ad)
> (have_ad ? EPT_VLT_WR : 0) |
> EPT_VLT_LADDR_VLD))
> vmx_inc_test_stage();
> - set_ept_pte(pml4, data_page1_pte, 2,
> + set_ept_pte(pml4, guest_pte_addr, 2,
> data_page1_pte_pte | (EPT_PRESENT));
> ept_sync(INVEPT_SINGLE, eptp);
> break;
>
Queued, thanks.
Paolo
