On 29/10/20 18:10, Jim Mattson wrote:
> If L1 allows L2 to modify CR4.OSXSAVE, then L0 kvm recalculates the
> guest's CPUID.01H:ECX.OSXSAVE bit when the L2 guest changes
> CR4.OSXSAVE via MOV-to-CR4. Verify that kvm also recalculates this
> CPUID bit when loading L1's CR4 from the save.cr4 field of the
> hsave area.
>
> Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
> Reviewed-by: Ricardo Koller <ricarkol@xxxxxxxxxx>
> Reviewed-by: Peter Shier <pshier@xxxxxxxxxx>
> ---
> x86/svm_tests.c | 35 +++++++++++++++++++++++++++++++++++
> 1 file changed, 35 insertions(+)
>
> diff --git a/x86/svm_tests.c b/x86/svm_tests.c
> index 3b0424a..e2455c8 100644
> --- a/x86/svm_tests.c
> +++ b/x86/svm_tests.c
> @@ -1917,6 +1917,40 @@ static bool reg_corruption_check(struct svm_test *test)
> * v2 tests
> */
>
> +/*
> + * Ensure that kvm recalculates the L1 guest's CPUID.01H:ECX.OSXSAVE
> + * after VM-exit from an L2 guest that sets CR4.OSXSAVE to a different
> + * value than in L1.
> + */
> +
> +static void svm_cr4_osxsave_test_guest(struct svm_test *test)
> +{
> + write_cr4(read_cr4() & ~X86_CR4_OSXSAVE);
> +}
> +
> +static void svm_cr4_osxsave_test(void)
> +{
> + if (!this_cpu_has(X86_FEATURE_XSAVE)) {
> + report_skip("XSAVE not detected");
> + return;
> + }
> +
> + if (!(read_cr4() & X86_CR4_OSXSAVE)) {
> + unsigned long cr4 = read_cr4() | X86_CR4_OSXSAVE;
> +
> + write_cr4(cr4);
> + vmcb->save.cr4 = cr4;
> + }
> +
> + report(cpuid_osxsave(), "CPUID.01H:ECX.XSAVE set before VMRUN");
> +
> + test_set_guest(svm_cr4_osxsave_test_guest);
> + report(svm_vmrun() == SVM_EXIT_VMMCALL,
> + "svm_cr4_osxsave_test_guest finished with VMMCALL");
> +
> + report(cpuid_osxsave(), "CPUID.01H:ECX.XSAVE set after VMRUN");
> +}
> +
> static void basic_guest_main(struct svm_test *test)
> {
> }
> @@ -2301,6 +2335,7 @@ struct svm_test svm_tests[] = {
> { "reg_corruption", default_supported, reg_corruption_prepare,
> default_prepare_gif_clear, reg_corruption_test,
> reg_corruption_finished, reg_corruption_check },
> + TEST(svm_cr4_osxsave_test),
> TEST(svm_guest_state_test),
> { NULL, NULL, NULL, NULL, NULL, NULL, NULL }
> };
>
Queued both, thanks.
Paolo
