* [PATCH 0/3] KVM: nSVM: Check addresses of MSR bitmap and IO bitmap tables on vmrun of nested guests
@ 2021-01-13 2:46 Krish Sadhukhan
2021-01-13 2:46 ` [PATCH 1/3] KVM: nSVM: Check addresses of MSR and IO bitmap Krish Sadhukhan
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Krish Sadhukhan @ 2021-01-13 2:46 UTC (permalink / raw
To: kvm; +Cc: pbonzini, jmattson, seanjc
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."
Patch# 1: Adds the KVM checks.
Patch# 2: Adds a test
Patch# 3: Replaces a hard-coded value with an available macro.
[PATCH 1/3] KVM: nSVM: Check addresses of MSR and IO bitmap
[PATCH 2/3] Test: nSVM: Test MSR and IO bitmap address
[PATCH 3/3] Test: SVM: Use ALIGN macro when aligning 'io_bitmap_area'
arch/x86/kvm/svm/nested.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
Krish Sadhukhan (1):
nSVM: Check addresses of MSR and IO bitmap
x86/svm.c | 2 +-
x86/svm_tests.c | 38 ++++++++++++++++++++++++++++++++++++++
2 files changed, 39 insertions(+), 1 deletion(-)
Krish Sadhukhan (2):
nSVM: Test MSR and IO bitmap address
SVM: Use ALIGN macro when aligning 'io_bitmap_area'
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 1/3] KVM: nSVM: Check addresses of MSR and IO bitmap
2021-01-13 2:46 [PATCH 0/3] KVM: nSVM: Check addresses of MSR bitmap and IO bitmap tables on vmrun of nested guests Krish Sadhukhan
@ 2021-01-13 2:46 ` Krish Sadhukhan
2021-01-13 17:43 ` Sean Christopherson
2021-01-13 2:46 ` [PATCH 2/3] Test: nSVM: Test MSR and IO bitmap address Krish Sadhukhan
2021-01-13 2:46 ` [PATCH 3/3] Test: SVM: Use ALIGN macro when aligning 'io_bitmap_area' Krish Sadhukhan
2 siblings, 1 reply; 5+ messages in thread
From: Krish Sadhukhan @ 2021-01-13 2:46 UTC (permalink / raw
To: kvm; +Cc: pbonzini, jmattson, seanjc
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."
Also check that these addresses are aligned on page boundary.
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
---
arch/x86/kvm/svm/nested.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index cb4c6ee10029..389a8108ddb5 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -211,8 +211,11 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu)
return true;
}
-static bool nested_vmcb_check_controls(struct vmcb_control_area *control)
+static bool nested_vmcb_check_controls(struct vcpu_svm *svm,
+ struct vmcb_control_area *control)
{
+ int maxphyaddr;
+
if ((vmcb_is_intercept(control, INTERCEPT_VMRUN)) == 0)
return false;
@@ -223,6 +226,14 @@ static bool nested_vmcb_check_controls(struct vmcb_control_area *control)
!npt_enabled)
return false;
+ maxphyaddr = cpuid_maxphyaddr(&svm->vcpu);
+ if (!IS_ALIGNED(control->msrpm_base_pa, PAGE_SIZE) ||
+ control->msrpm_base_pa >> maxphyaddr)
+ return false;
+ if (!IS_ALIGNED(control->iopm_base_pa, PAGE_SIZE) ||
+ control->iopm_base_pa >> maxphyaddr)
+ return false;
+
return true;
}
@@ -258,7 +269,7 @@ static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
if (!kvm_is_valid_cr4(&svm->vcpu, vmcb12->save.cr4))
return false;
- return nested_vmcb_check_controls(&vmcb12->control);
+ return nested_vmcb_check_controls(svm, &vmcb12->control);
}
static void load_nested_vmcb_control(struct vcpu_svm *svm,
@@ -1173,7 +1184,7 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
goto out_free;
ret = -EINVAL;
- if (!nested_vmcb_check_controls(ctl))
+ if (!nested_vmcb_check_controls(svm, ctl))
goto out_free;
/*
--
2.27.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/3] Test: nSVM: Test MSR and IO bitmap address
2021-01-13 2:46 [PATCH 0/3] KVM: nSVM: Check addresses of MSR bitmap and IO bitmap tables on vmrun of nested guests Krish Sadhukhan
2021-01-13 2:46 ` [PATCH 1/3] KVM: nSVM: Check addresses of MSR and IO bitmap Krish Sadhukhan
@ 2021-01-13 2:46 ` Krish Sadhukhan
2021-01-13 2:46 ` [PATCH 3/3] Test: SVM: Use ALIGN macro when aligning 'io_bitmap_area' Krish Sadhukhan
2 siblings, 0 replies; 5+ messages in thread
From: Krish Sadhukhan @ 2021-01-13 2:46 UTC (permalink / raw
To: kvm; +Cc: pbonzini, jmattson, seanjc
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."
Also test that these addresses are aligned on page boundary.
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
---
x86/svm_tests.c | 38 ++++++++++++++++++++++++++++++++++++++
1 file changed, 38 insertions(+)
diff --git a/x86/svm_tests.c b/x86/svm_tests.c
index dc86efd..929a3e1 100644
--- a/x86/svm_tests.c
+++ b/x86/svm_tests.c
@@ -2304,6 +2304,43 @@ static void test_dr(void)
vmcb->save.dr7 = dr_saved;
}
+extern u8 msr_bitmap_area[];
+extern u8 io_bitmap_area[];
+
+#define TEST_BITMAP_ADDR(prot_type, bitmap_addr, msg) { \
+ vmcb->control.intercept = 1ULL << prot_type; \
+ addr_unalign = virt_to_phys(bitmap_addr); \
+ if (prot_type == INTERCEPT_MSR_PROT) \
+ vmcb->control.msrpm_base_pa = addr_unalign; \
+ else \
+ vmcb->control.iopm_base_pa = addr_unalign; \
+ report(svm_vmrun() == SVM_EXIT_ERR, "Test %s address: %lx", msg,\
+ addr_unalign); \
+ vmcb->control.msrpm_base_pa = addr_spill_beyond_ram; \
+ report(svm_vmrun() == SVM_EXIT_ERR, "Test %s address: %lx", msg,\
+ addr_spill_beyond_ram); \
+} \
+
+/*
+ * 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 addr_unalign;
+ u64 addr_spill_beyond_ram =
+ (u64)(((u64)1 << cpuid_maxphyaddr()) - 4096);
+
+ /* MSR bitmap address */
+ TEST_BITMAP_ADDR(INTERCEPT_MSR_PROT, msr_bitmap_area, "MSRPM");
+
+ /* MSR bitmap address */
+ TEST_BITMAP_ADDR(INTERCEPT_IOIO_PROT, io_bitmap_area, "IOPM");
+}
+
static void svm_guest_state_test(void)
{
test_set_guest(basic_guest_main);
@@ -2313,6 +2350,7 @@ static void svm_guest_state_test(void)
test_cr3();
test_cr4();
test_dr();
+ test_msrpm_iopm_bitmap_addrs();
}
struct svm_test svm_tests[] = {
--
2.27.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 3/3] Test: SVM: Use ALIGN macro when aligning 'io_bitmap_area'
2021-01-13 2:46 [PATCH 0/3] KVM: nSVM: Check addresses of MSR bitmap and IO bitmap tables on vmrun of nested guests Krish Sadhukhan
2021-01-13 2:46 ` [PATCH 1/3] KVM: nSVM: Check addresses of MSR and IO bitmap Krish Sadhukhan
2021-01-13 2:46 ` [PATCH 2/3] Test: nSVM: Test MSR and IO bitmap address Krish Sadhukhan
@ 2021-01-13 2:46 ` Krish Sadhukhan
2 siblings, 0 replies; 5+ messages in thread
From: Krish Sadhukhan @ 2021-01-13 2:46 UTC (permalink / raw
To: kvm; +Cc: pbonzini, jmattson, seanjc
Since the macro is available and we already use it for MSR bitmap table, use
it for aligning IO bitmap table also.
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
---
x86/svm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/x86/svm.c b/x86/svm.c
index a1808c7..846cf2a 100644
--- a/x86/svm.c
+++ b/x86/svm.c
@@ -298,7 +298,7 @@ static void setup_svm(void)
wrmsr(MSR_EFER, rdmsr(MSR_EFER) | EFER_SVME);
wrmsr(MSR_EFER, rdmsr(MSR_EFER) | EFER_NX);
- io_bitmap = (void *) (((ulong)io_bitmap_area + 4095) & ~4095);
+ io_bitmap = (void *) ALIGN((ulong)io_bitmap_area, PAGE_SIZE);
msr_bitmap = (void *) ALIGN((ulong)msr_bitmap_area, PAGE_SIZE);
--
2.27.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH 1/3] KVM: nSVM: Check addresses of MSR and IO bitmap
2021-01-13 2:46 ` [PATCH 1/3] KVM: nSVM: Check addresses of MSR and IO bitmap Krish Sadhukhan
@ 2021-01-13 17:43 ` Sean Christopherson
0 siblings, 0 replies; 5+ messages in thread
From: Sean Christopherson @ 2021-01-13 17:43 UTC (permalink / raw
To: Krish Sadhukhan; +Cc: kvm, pbonzini, jmattson
On Wed, Jan 13, 2021, Krish Sadhukhan wrote:
> 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."
>
> Also check that these addresses are aligned on page boundary.
>
> Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
> ---
> arch/x86/kvm/svm/nested.c | 17 ++++++++++++++---
> 1 file changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
> index cb4c6ee10029..389a8108ddb5 100644
> --- a/arch/x86/kvm/svm/nested.c
> +++ b/arch/x86/kvm/svm/nested.c
> @@ -211,8 +211,11 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu)
> return true;
> }
>
> -static bool nested_vmcb_check_controls(struct vmcb_control_area *control)
> +static bool nested_vmcb_check_controls(struct vcpu_svm *svm,
It's probably worth passing vcpu instead of svm. svm_set_nested_state() already
takes vcpu, and nested_vmcb_checks() could easily do the same (in a separate
cleanup), especially if nested_svm_vmrun() were cleaned up to capture vcpu in a
local variable instead of constantly doing &svm->vcpu.
> + struct vmcb_control_area *control)
> {
> + int maxphyaddr;
> +
> if ((vmcb_is_intercept(control, INTERCEPT_VMRUN)) == 0)
> return false;
>
> @@ -223,6 +226,14 @@ static bool nested_vmcb_check_controls(struct vmcb_control_area *control)
> !npt_enabled)
> return false;
>
> + maxphyaddr = cpuid_maxphyaddr(&svm->vcpu);
> + if (!IS_ALIGNED(control->msrpm_base_pa, PAGE_SIZE) ||
> + control->msrpm_base_pa >> maxphyaddr)
These can use page_address_valid().
Unrelated to this patch, we really should consolidate all the different flavors
of open-coded variants of maxphyaddr checks to use kvm_vcpu_is_illegal_gpa(),
and maybe add a helper to do an arbitrary alignment check. VMX has a handful of
checks that fit that pattern and aren't exactly intuitive at first glance.
We could also add a kvm_vcpu_rsvd_gpa_bits() too. Somehow even that has
multiple open-coded variants.
I'll add those cleanups to the todo list.
> + return false;
> + if (!IS_ALIGNED(control->iopm_base_pa, PAGE_SIZE) ||
> + control->iopm_base_pa >> maxphyaddr)
> + return false;
> +
> return true;
> }
>
> @@ -258,7 +269,7 @@ static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
> if (!kvm_is_valid_cr4(&svm->vcpu, vmcb12->save.cr4))
> return false;
>
> - return nested_vmcb_check_controls(&vmcb12->control);
> + return nested_vmcb_check_controls(svm, &vmcb12->control);
> }
>
> static void load_nested_vmcb_control(struct vcpu_svm *svm,
> @@ -1173,7 +1184,7 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
> goto out_free;
>
> ret = -EINVAL;
> - if (!nested_vmcb_check_controls(ctl))
> + if (!nested_vmcb_check_controls(svm, ctl))
> goto out_free;
>
> /*
> --
> 2.27.0
>
^ permalink raw reply [flat|nested] 5+ messages in thread
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Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2021-01-13 2:46 [PATCH 0/3] KVM: nSVM: Check addresses of MSR bitmap and IO bitmap tables on vmrun of nested guests Krish Sadhukhan
2021-01-13 2:46 ` [PATCH 1/3] KVM: nSVM: Check addresses of MSR and IO bitmap Krish Sadhukhan
2021-01-13 17:43 ` Sean Christopherson
2021-01-13 2:46 ` [PATCH 2/3] Test: nSVM: Test MSR and IO bitmap address Krish Sadhukhan
2021-01-13 2:46 ` [PATCH 3/3] Test: SVM: Use ALIGN macro when aligning 'io_bitmap_area' Krish Sadhukhan
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