[PATCH 4/5 v6] nSVM: Test addresses of MSR and IO permissions maps

Krish Sadhukhan
2021-04-02T01:33:06Z

According to section "Canonicalization and Consistency Checks" in APM vol 2,
the following guest state is illegal:

"The MSR or IOIO intercept tables extend to a physical address that
is greater than or equal to the maximum supported physical address."

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
(cherry picked from commit 0513cf071255c7d5a1b7a813d017bbdd2d1da263)
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
---
x86/svm_tests.c | 42 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/x86/svm_tests.c b/x86/svm_tests.c
index 29a0b59..7014c40 100644
--- a/x86/svm_tests.c
+++ b/x86/svm_tests.c
@@ -2304,15 +2304,55 @@ static void test_dr(void)
vmcb->save.dr7 = dr_saved;
}

+/*
+ * If the MSR or IOIO intercept table extends to a physical address that
+ * is greater than or equal to the maximum supported physical address, the
+ * guest state is illegal.
+ *
+ * [APM vol 2]
+ */
+static void test_msrpm_iopm_bitmap_addrs(void)
+{
+ u64 saved_intercepts = vmcb->control.intercept;
+ u64 bitmap_addr_1 =
+ (u64)(((u64)1 << cpuid_maxphyaddr()) - PAGE_SIZE);
+ u64 bitmap_addr_2 =
+ (u64)(((u64)1 << cpuid_maxphyaddr()) - PAGE_SIZE * 2);
+
+ /*
+ * MSR bitmap address
+ */
+ vmcb->control.intercept = saved_intercepts | 1ULL << INTERCEPT_MSR_PROT;
+ vmcb->control.msrpm_base_pa = bitmap_addr_1;
+ report(svm_vmrun() == SVM_EXIT_ERR, "Test MSRPM address: %lx",
+ bitmap_addr_1);
+ vmcb->control.msrpm_base_pa = bitmap_addr_2;
+ report(svm_vmrun() == SVM_EXIT_ERR, "Test MSRPM address: %lx",
+ bitmap_addr_2);
+
+ /*
+ * IOIO bitmap address
+ */
+ vmcb->control.intercept = saved_intercepts | 1ULL << INTERCEPT_IOIO_PROT;
+ vmcb->control.iopm_base_pa = bitmap_addr_1;
+ report(svm_vmrun() == SVM_EXIT_ERR, "Test IOPM address: %lx",
+ bitmap_addr_1);
+ vmcb->control.iopm_base_pa = bitmap_addr_2 += 1;
+ report(svm_vmrun() == SVM_EXIT_ERR, "Test IOPM address: %lx",
+ bitmap_addr_2);
+
+ vmcb->control.intercept = saved_intercepts;
+}
+
static void svm_guest_state_test(void)
{
test_set_guest(basic_guest_main);
-
test_efer();
test_cr0();
test_cr3();
test_cr4();
test_dr();
+ test_msrpm_iopm_bitmap_addrs();
}

--
2.27.0