* [PATCH 0/3 v2] KVM: nSVM: Check addresses of MSR bitmap and IO bitmap tables on vmrun of nested guests
@ 2021-01-16 2:20 Krish Sadhukhan
2021-01-16 2:20 ` [PATCH 1/3 v2] nSVM: Check addresses of MSR and IO bitmap Krish Sadhukhan
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Krish Sadhukhan @ 2021-01-16 2:20 UTC (permalink / raw)
To: kvm; +Cc: pbonzini, jmattson, seanjc
v1 -> v2:
In patch# 1, the parameter to nested_vmcb_check_controls() has been
changed to 'struct kvm_vcpu' from 'struct vcpu_svm'. This necessiated
relevant changes to its callers.
Also, the new checks in nested_vmcb_check_controls() now use
page_address_valid() instead of duplicating code.
It has also been rebased to v5.11-rc3.
[PATCH 1/3 v2] nSVM: Check addresses of MSR and IO bitmap
[PATCH 2/3 v2] Test: nSVM: Test MSR and IO bitmap address
[PATCH 3/3 v2] Test: SVM: Use ALIGN macro when aligning 'io_bitmap_area'
arch/x86/kvm/svm/nested.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 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] 6+ messages in thread
* [PATCH 1/3 v2] nSVM: Check addresses of MSR and IO bitmap
2021-01-16 2:20 [PATCH 0/3 v2] KVM: nSVM: Check addresses of MSR bitmap and IO bitmap tables on vmrun of nested guests Krish Sadhukhan
@ 2021-01-16 2:20 ` Krish Sadhukhan
2021-01-20 0:45 ` Sean Christopherson
2021-01-16 2:20 ` [PATCH 2/3 v2] Test: nSVM: Test MSR and IO bitmap address Krish Sadhukhan
2021-01-16 2:20 ` [PATCH 3/3 v2] Test: SVM: Use ALIGN macro when aligning 'io_bitmap_area' Krish Sadhukhan
2 siblings, 1 reply; 6+ messages in thread
From: Krish Sadhukhan @ 2021-01-16 2:20 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 | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index cb4c6ee10029..2419f392a13d 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -211,7 +211,8 @@ 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 kvm_vcpu *vcpu,
+ struct vmcb_control_area *control)
{
if ((vmcb_is_intercept(control, INTERCEPT_VMRUN)) == 0)
return false;
@@ -223,10 +224,15 @@ static bool nested_vmcb_check_controls(struct vmcb_control_area *control)
!npt_enabled)
return false;
+ if (!page_address_valid(vcpu, control->msrpm_base_pa))
+ return false;
+ if (!page_address_valid(vcpu, control->iopm_base_pa))
+ return false;
+
return true;
}
-static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
+static bool nested_vmcb_checks(struct kvm_vcpu *vcpu, struct vmcb *vmcb12)
{
bool vmcb12_lma;
@@ -255,10 +261,10 @@ static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
(vmcb12->save.cr3 & MSR_CR3_LONG_MBZ_MASK))
return false;
}
- if (!kvm_is_valid_cr4(&svm->vcpu, vmcb12->save.cr4))
+ if (!kvm_is_valid_cr4(vcpu, vmcb12->save.cr4))
return false;
- return nested_vmcb_check_controls(&vmcb12->control);
+ return nested_vmcb_check_controls(vcpu, &vmcb12->control);
}
static void load_nested_vmcb_control(struct vcpu_svm *svm,
@@ -485,7 +491,7 @@ int nested_svm_vmrun(struct vcpu_svm *svm)
if (WARN_ON_ONCE(!svm->nested.initialized))
return -EINVAL;
- if (!nested_vmcb_checks(svm, vmcb12)) {
+ if (!nested_vmcb_checks(&svm->vcpu, vmcb12)) {
vmcb12->control.exit_code = SVM_EXIT_ERR;
vmcb12->control.exit_code_hi = 0;
vmcb12->control.exit_info_1 = 0;
@@ -1173,7 +1179,7 @@ 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(vcpu, ctl))
goto out_free;
/*
--
2.27.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/3 v2] Test: nSVM: Test MSR and IO bitmap address
2021-01-16 2:20 [PATCH 0/3 v2] KVM: nSVM: Check addresses of MSR bitmap and IO bitmap tables on vmrun of nested guests Krish Sadhukhan
2021-01-16 2:20 ` [PATCH 1/3 v2] nSVM: Check addresses of MSR and IO bitmap Krish Sadhukhan
@ 2021-01-16 2:20 ` Krish Sadhukhan
2021-01-16 2:20 ` [PATCH 3/3 v2] Test: SVM: Use ALIGN macro when aligning 'io_bitmap_area' Krish Sadhukhan
2 siblings, 0 replies; 6+ messages in thread
From: Krish Sadhukhan @ 2021-01-16 2:20 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] 6+ messages in thread
* [PATCH 3/3 v2] Test: SVM: Use ALIGN macro when aligning 'io_bitmap_area'
2021-01-16 2:20 [PATCH 0/3 v2] KVM: nSVM: Check addresses of MSR bitmap and IO bitmap tables on vmrun of nested guests Krish Sadhukhan
2021-01-16 2:20 ` [PATCH 1/3 v2] nSVM: Check addresses of MSR and IO bitmap Krish Sadhukhan
2021-01-16 2:20 ` [PATCH 2/3 v2] Test: nSVM: Test MSR and IO bitmap address Krish Sadhukhan
@ 2021-01-16 2:20 ` Krish Sadhukhan
2 siblings, 0 replies; 6+ messages in thread
From: Krish Sadhukhan @ 2021-01-16 2:20 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] 6+ messages in thread
* Re: [PATCH 1/3 v2] nSVM: Check addresses of MSR and IO bitmap
2021-01-16 2:20 ` [PATCH 1/3 v2] nSVM: Check addresses of MSR and IO bitmap Krish Sadhukhan
@ 2021-01-20 0:45 ` Sean Christopherson
2021-01-21 0:36 ` Krish Sadhukhan
0 siblings, 1 reply; 6+ messages in thread
From: Sean Christopherson @ 2021-01-20 0:45 UTC (permalink / raw)
To: Krish Sadhukhan; +Cc: kvm, pbonzini, jmattson
On Sat, Jan 16, 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 | 18 ++++++++++++------
> 1 file changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
> index cb4c6ee10029..2419f392a13d 100644
> --- a/arch/x86/kvm/svm/nested.c
> +++ b/arch/x86/kvm/svm/nested.c
> @@ -211,7 +211,8 @@ 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 kvm_vcpu *vcpu,
> + struct vmcb_control_area *control)
> {
> if ((vmcb_is_intercept(control, INTERCEPT_VMRUN)) == 0)
> return false;
> @@ -223,10 +224,15 @@ static bool nested_vmcb_check_controls(struct vmcb_control_area *control)
> !npt_enabled)
> return false;
>
> + if (!page_address_valid(vcpu, control->msrpm_base_pa))
> + return false;
> + if (!page_address_valid(vcpu, control->iopm_base_pa))
These checks are wrong. The MSRPM is 8kb in size, and the IOPM is 12kb, and the
APM explicitly states that the last byte is checked:
if the address of the last byte in the table is greater than or equal to the
maximum supported physical address, this is treated as illegal VMCB state and
causes a #VMEXIT(VMEXIT_INVALID).
KVM can't check just the last byte, as that would fail to detect a wrap of the
64-bit boundary. Might be worth adding yet another helper? I think this will
work, though I'm sure Paolo has a much more clever solution :-)
static inline bool page_range_valid(struct kvm_vcpu *vcpu, gpa_t gpa, int size)
{
gpa_t last_page = gpa + size - PAGE_SIZE;
if (last_page < gpa)
return false;
return page_address_valid(last_page);
}
Note, the IOPM is 12kb in size, but KVM allocates and initializes 16kb, i.e.
using IOPM_ALLOC_ORDER for the check would be wrong. Maybe define the actual
size for both bitmaps and use get_order() instead of hardcoding the order? That
would make it easy to "fix" svm_hardware_setup() so that it doesn't initialize
unused memory.
> + return false;
> +
> return true;
> }
>
> -static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
> +static bool nested_vmcb_checks(struct kvm_vcpu *vcpu, struct vmcb *vmcb12)
> {
> bool vmcb12_lma;
>
> @@ -255,10 +261,10 @@ static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
> (vmcb12->save.cr3 & MSR_CR3_LONG_MBZ_MASK))
> return false;
> }
> - if (!kvm_is_valid_cr4(&svm->vcpu, vmcb12->save.cr4))
> + if (!kvm_is_valid_cr4(vcpu, vmcb12->save.cr4))
> return false;
>
> - return nested_vmcb_check_controls(&vmcb12->control);
> + return nested_vmcb_check_controls(vcpu, &vmcb12->control);
> }
>
> static void load_nested_vmcb_control(struct vcpu_svm *svm,
> @@ -485,7 +491,7 @@ int nested_svm_vmrun(struct vcpu_svm *svm)
> if (WARN_ON_ONCE(!svm->nested.initialized))
> return -EINVAL;
>
> - if (!nested_vmcb_checks(svm, vmcb12)) {
> + if (!nested_vmcb_checks(&svm->vcpu, vmcb12)) {
> vmcb12->control.exit_code = SVM_EXIT_ERR;
> vmcb12->control.exit_code_hi = 0;
> vmcb12->control.exit_info_1 = 0;
> @@ -1173,7 +1179,7 @@ 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(vcpu, ctl))
> goto out_free;
>
> /*
> --
> 2.27.0
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/3 v2] nSVM: Check addresses of MSR and IO bitmap
2021-01-20 0:45 ` Sean Christopherson
@ 2021-01-21 0:36 ` Krish Sadhukhan
0 siblings, 0 replies; 6+ messages in thread
From: Krish Sadhukhan @ 2021-01-21 0:36 UTC (permalink / raw)
To: Sean Christopherson; +Cc: kvm, pbonzini, jmattson
On 1/19/21 4:45 PM, Sean Christopherson wrote:
> On Sat, Jan 16, 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 | 18 ++++++++++++------
>> 1 file changed, 12 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
>> index cb4c6ee10029..2419f392a13d 100644
>> --- a/arch/x86/kvm/svm/nested.c
>> +++ b/arch/x86/kvm/svm/nested.c
>> @@ -211,7 +211,8 @@ 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 kvm_vcpu *vcpu,
>> + struct vmcb_control_area *control)
>> {
>> if ((vmcb_is_intercept(control, INTERCEPT_VMRUN)) == 0)
>> return false;
>> @@ -223,10 +224,15 @@ static bool nested_vmcb_check_controls(struct vmcb_control_area *control)
>> !npt_enabled)
>> return false;
>>
>> + if (!page_address_valid(vcpu, control->msrpm_base_pa))
>> + return false;
>> + if (!page_address_valid(vcpu, control->iopm_base_pa))
> These checks are wrong. The MSRPM is 8kb in size, and the IOPM is 12kb, and the
> APM explicitly states that the last byte is checked:
>
> if the address of the last byte in the table is greater than or equal to the
> maximum supported physical address, this is treated as illegal VMCB state and
> causes a #VMEXIT(VMEXIT_INVALID).
>
> KVM can't check just the last byte, as that would fail to detect a wrap of the
> 64-bit boundary. Might be worth adding yet another helper? I think this will
> work, though I'm sure Paolo has a much more clever solution :-)
>
> static inline bool page_range_valid(struct kvm_vcpu *vcpu, gpa_t gpa, int size)
> {
> gpa_t last_page = gpa + size - PAGE_SIZE;
>
> if (last_page < gpa)
> return false;
>
> return page_address_valid(last_page);
> }
>
> Note, the IOPM is 12kb in size, but KVM allocates and initializes 16kb, i.e.
> using IOPM_ALLOC_ORDER for the check would be wrong. Maybe define the actual
> size for both bitmaps and use get_order() instead of hardcoding the order? That
> would make it easy to "fix" svm_hardware_setup() so that it doesn't initialize
> unused memory.
Is there any issues with using alloc_pages_exact() instead of
alloc_pages() for allocating the IOPM bitmap ?
>
>> + return false;
>> +
>> return true;
>> }
>>
>> -static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
>> +static bool nested_vmcb_checks(struct kvm_vcpu *vcpu, struct vmcb *vmcb12)
>> {
>> bool vmcb12_lma;
>>
>> @@ -255,10 +261,10 @@ static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
>> (vmcb12->save.cr3 & MSR_CR3_LONG_MBZ_MASK))
>> return false;
>> }
>> - if (!kvm_is_valid_cr4(&svm->vcpu, vmcb12->save.cr4))
>> + if (!kvm_is_valid_cr4(vcpu, vmcb12->save.cr4))
>> return false;
>>
>> - return nested_vmcb_check_controls(&vmcb12->control);
>> + return nested_vmcb_check_controls(vcpu, &vmcb12->control);
>> }
>>
>> static void load_nested_vmcb_control(struct vcpu_svm *svm,
>> @@ -485,7 +491,7 @@ int nested_svm_vmrun(struct vcpu_svm *svm)
>> if (WARN_ON_ONCE(!svm->nested.initialized))
>> return -EINVAL;
>>
>> - if (!nested_vmcb_checks(svm, vmcb12)) {
>> + if (!nested_vmcb_checks(&svm->vcpu, vmcb12)) {
>> vmcb12->control.exit_code = SVM_EXIT_ERR;
>> vmcb12->control.exit_code_hi = 0;
>> vmcb12->control.exit_info_1 = 0;
>> @@ -1173,7 +1179,7 @@ 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(vcpu, ctl))
>> goto out_free;
>>
>> /*
>> --
>> 2.27.0
>>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-01-21 1:10 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2021-01-16 2:20 [PATCH 0/3 v2] KVM: nSVM: Check addresses of MSR bitmap and IO bitmap tables on vmrun of nested guests Krish Sadhukhan
2021-01-16 2:20 ` [PATCH 1/3 v2] nSVM: Check addresses of MSR and IO bitmap Krish Sadhukhan
2021-01-20 0:45 ` Sean Christopherson
2021-01-21 0:36 ` Krish Sadhukhan
2021-01-16 2:20 ` [PATCH 2/3 v2] Test: nSVM: Test MSR and IO bitmap address Krish Sadhukhan
2021-01-16 2:20 ` [PATCH 3/3 v2] Test: SVM: Use ALIGN macro when aligning 'io_bitmap_area' Krish Sadhukhan
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