On 30/06/20 11:45, Nadav Amit wrote:
> According to AMD manual bit 8 in PDPE is not reserved, but bit 7.
>
> Signed-off-by: Nadav Amit <namit@xxxxxxxxxx>
> ---
> x86/svm_tests.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/x86/svm_tests.c b/x86/svm_tests.c
> index 92cefaf..323031f 100644
> --- a/x86/svm_tests.c
> +++ b/x86/svm_tests.c
> @@ -825,13 +825,13 @@ static void npt_rsvd_pfwalk_prepare(struct svm_test *test)
> vmcb_ident(vmcb);
>
> pdpe = npt_get_pdpe();
> - pdpe[0] |= (1ULL << 8);
> + pdpe[0] |= (1ULL << 7);
> }
>
> static bool npt_rsvd_pfwalk_check(struct svm_test *test)
> {
> u64 *pdpe = npt_get_pdpe();
> - pdpe[0] &= ~(1ULL << 8);
> + pdpe[0] &= ~(1ULL << 7);
>
> return (vmcb->control.exit_code == SVM_EXIT_NPF)
> && (vmcb->control.exit_info_1 == 0x20000000eULL);
>
Wait, bit 7 is not reserved, it's the PS bit. We need to use the PML4E instead (and
then using bit 7 or bit 8 is irrelevant):
diff --git a/x86/svm.c b/x86/svm.c
index 0fcad8d..62907fd 100644
--- a/x86/svm.c
+++ b/x86/svm.c
@@ -49,6 +49,11 @@ u64 *npt_get_pdpe(void)
return pdpe;
}
+u64 *npt_get_pml4e(void)
+{
+ return pml4e;
+}
+
bool smp_supported(void)
{
return cpu_count() > 1;
diff --git a/x86/svm.h b/x86/svm.h
index 645deb7..8d688b6 100644
--- a/x86/svm.h
+++ b/x86/svm.h
@@ -365,6 +365,7 @@ typedef void (*test_guest_func)(struct svm_test *);
u64 *npt_get_pte(u64 address);
u64 *npt_get_pde(u64 address);
u64 *npt_get_pdpe(void);
+u64 *npt_get_pml4e(void);
bool smp_supported(void);
bool default_supported(void);
void default_prepare(struct svm_test *test);
diff --git a/x86/svm_tests.c b/x86/svm_tests.c
index 92cefaf..b540527 100644
--- a/x86/svm_tests.c
+++ b/x86/svm_tests.c
@@ -824,13 +824,13 @@ static void npt_rsvd_pfwalk_prepare(struct svm_test *test)
u64 *pdpe;
vmcb_ident(vmcb);
- pdpe = npt_get_pdpe();
+ pdpe = npt_get_pml4e();
pdpe[0] |= (1ULL << 8);
}
static bool npt_rsvd_pfwalk_check(struct svm_test *test)
{
- u64 *pdpe = npt_get_pdpe();
+ u64 *pdpe = npt_get_pml4e();
pdpe[0] &= ~(1ULL << 8);
return (vmcb->control.exit_code == SVM_EXIT_NPF)
