> On May 3, 2019, at 10:49 AM, nadav.amit@xxxxxxxxx wrote:
>
> From: Nadav Amit <nadav.amit@xxxxxxxxx>
>
> On EPT violation, the exit qualifications may have some undefined bits.
>
> Bit 6 is undefined if "mode-based execute control" is 0.
>
> Bits 9-11 are undefined unless the processor supports advanced VM-exit
> information for EPT violations.
>
> Right now on KVM these bits are always undefined inside the VM (i.e., in
> an emulated VM-exit). Mask these bits to avoid potential false
> indication of failures.
>
> Signed-off-by: Nadav Amit <nadav.amit@xxxxxxxxx>
> ---
> x86/vmx.h | 20 ++++++++++++--------
> x86/vmx_tests.c | 4 ++++
> 2 files changed, 16 insertions(+), 8 deletions(-)
>
> diff --git a/x86/vmx.h b/x86/vmx.h
> index cc377ef..5053d6f 100644
> --- a/x86/vmx.h
> +++ b/x86/vmx.h
> @@ -603,16 +603,20 @@ enum vm_instruction_error_number {
> #define EPT_ADDR_MASK GENMASK_ULL(51, 12)
> #define PAGE_MASK_2M (~(PAGE_SIZE_2M-1))
>
> -#define EPT_VLT_RD 1
> -#define EPT_VLT_WR (1 << 1)
> -#define EPT_VLT_FETCH (1 << 2)
> -#define EPT_VLT_PERM_RD (1 << 3)
> -#define EPT_VLT_PERM_WR (1 << 4)
> -#define EPT_VLT_PERM_EX (1 << 5)
> +#define EPT_VLT_RD (1ull << 0)
> +#define EPT_VLT_WR (1ull << 1)
> +#define EPT_VLT_FETCH (1ull << 2)
> +#define EPT_VLT_PERM_RD (1ull << 3)
> +#define EPT_VLT_PERM_WR (1ull << 4)
> +#define EPT_VLT_PERM_EX (1ull << 5)
> +#define EPT_VLT_PERM_USER_EX (1ull << 6)
> #define EPT_VLT_PERMS (EPT_VLT_PERM_RD | EPT_VLT_PERM_WR | \
> EPT_VLT_PERM_EX)
> -#define EPT_VLT_LADDR_VLD (1 << 7)
> -#define EPT_VLT_PADDR (1 << 8)
> +#define EPT_VLT_LADDR_VLD (1ull << 7)
> +#define EPT_VLT_PADDR (1ull << 8)
> +#define EPT_VLT_GUEST_USER (1ull << 9)
> +#define EPT_VLT_GUEST_WR (1ull << 10)
> +#define EPT_VLT_GUEST_EX (1ull << 11)
>
> #define MAGIC_VAL_1 0x12345678ul
> #define MAGIC_VAL_2 0x87654321ul
> diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
> index c52ebc6..b4129e1 100644
> --- a/x86/vmx_tests.c
> +++ b/x86/vmx_tests.c
> @@ -2365,6 +2365,10 @@ static void do_ept_violation(bool leaf, enum ept_access_op op,
>
> qual = vmcs_read(EXI_QUALIFICATION);
>
> + /* Mask undefined bits (which may later be defined in certain cases). */
> + qual &= ~(EPT_VLT_GUEST_USER | EPT_VLT_GUEST_WR | EPT_VLT_GUEST_EX |
> + EPT_VLT_PERM_USER_EX);
> +
> diagnose_ept_violation_qual(expected_qual, qual);
> TEST_EXPECT_EQ(expected_qual, qual);
>
> --
> 2.17.1
Ping.
