* [PATCH v3 1/5] KVM: VMX: Use precomputed MAXPHYADDR for RTIT base MSR check
2020-09-24 19:42 [PATCH v3 0/5] KVM: VMX: Clean up RTIT MAXPHYADDR usage Sean Christopherson
@ 2020-09-24 19:42 ` Sean Christopherson
2020-09-24 19:42 ` [PATCH v3 2/5] KVM: x86: Unexport cpuid_query_maxphyaddr() Sean Christopherson
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Sean Christopherson @ 2020-09-24 19:42 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, kvm, linux-kernel
Use cpuid_maxphyaddr() instead of cpuid_query_maxphyaddr() for the
RTIT base MSR check. There is no reason to recompute MAXPHYADDR as the
precomputed version is synchronized with CPUID updates, and
MSR_IA32_RTIT_OUTPUT_BASE is not written between stuffing CPUID and
refreshing vcpu->arch.maxphyaddr.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/vmx/vmx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 6f9a0c6d5dc5..be82da055fc4 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -147,7 +147,7 @@ module_param_named(preemption_timer, enable_preemption_timer, bool, S_IRUGO);
RTIT_STATUS_BYTECNT))
#define MSR_IA32_RTIT_OUTPUT_BASE_MASK \
- (~((1UL << cpuid_query_maxphyaddr(vcpu)) - 1) | 0x7f)
+ (~((1UL << cpuid_maxphyaddr(vcpu)) - 1) | 0x7f)
/*
* These 2 parameters are used to config the controls for Pause-Loop Exiting:
--
2.28.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v3 2/5] KVM: x86: Unexport cpuid_query_maxphyaddr()
2020-09-24 19:42 [PATCH v3 0/5] KVM: VMX: Clean up RTIT MAXPHYADDR usage Sean Christopherson
2020-09-24 19:42 ` [PATCH v3 1/5] KVM: VMX: Use precomputed MAXPHYADDR for RTIT base MSR check Sean Christopherson
@ 2020-09-24 19:42 ` Sean Christopherson
2020-09-24 19:42 ` [PATCH v3 3/5] KVM: VMX: Replace MSR_IA32_RTIT_OUTPUT_BASE_MASK with helper function Sean Christopherson
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Sean Christopherson @ 2020-09-24 19:42 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, kvm, linux-kernel
Stop exporting cpuid_query_maxphyaddr() now that it's not being abused
by VMX.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/cpuid.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 3fd6eec202d7..dc95b638911e 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -186,7 +186,6 @@ int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
not_found:
return 36;
}
-EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);
/* when an old userspace process fills a new kernel module */
int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
--
2.28.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v3 3/5] KVM: VMX: Replace MSR_IA32_RTIT_OUTPUT_BASE_MASK with helper function
2020-09-24 19:42 [PATCH v3 0/5] KVM: VMX: Clean up RTIT MAXPHYADDR usage Sean Christopherson
2020-09-24 19:42 ` [PATCH v3 1/5] KVM: VMX: Use precomputed MAXPHYADDR for RTIT base MSR check Sean Christopherson
2020-09-24 19:42 ` [PATCH v3 2/5] KVM: x86: Unexport cpuid_query_maxphyaddr() Sean Christopherson
@ 2020-09-24 19:42 ` Sean Christopherson
2020-09-24 19:42 ` [PATCH v3 4/5] KVM: x86: Move illegal GPA helper out of the MMU code Sean Christopherson
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Sean Christopherson @ 2020-09-24 19:42 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, kvm, linux-kernel
Replace the subtly not-a-constant MSR_IA32_RTIT_OUTPUT_BASE_MASK with a
proper helper function to check whether or not the specified base is
valid. Blindly referencing the local 'vcpu' is especially nasty.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/vmx/vmx.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index be82da055fc4..0d41faf63b57 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -146,9 +146,6 @@ module_param_named(preemption_timer, enable_preemption_timer, bool, S_IRUGO);
RTIT_STATUS_ERROR | RTIT_STATUS_STOPPED | \
RTIT_STATUS_BYTECNT))
-#define MSR_IA32_RTIT_OUTPUT_BASE_MASK \
- (~((1UL << cpuid_maxphyaddr(vcpu)) - 1) | 0x7f)
-
/*
* These 2 parameters are used to config the controls for Pause-Loop Exiting:
* ple_gap: upper bound on the amount of time between two successive
@@ -1037,6 +1034,12 @@ static inline bool pt_can_write_msr(struct vcpu_vmx *vmx)
!(vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN);
}
+static inline bool pt_output_base_valid(struct kvm_vcpu *vcpu, u64 base)
+{
+ /* The base must be 128-byte aligned and a legal physical address. */
+ return !(base & (~((1UL << cpuid_maxphyaddr(vcpu)) - 1) | 0x7f));
+}
+
static inline void pt_load_msr(struct pt_ctx *ctx, u32 addr_range)
{
u32 i;
@@ -2167,7 +2170,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
!intel_pt_validate_cap(vmx->pt_desc.caps,
PT_CAP_single_range_output))
return 1;
- if (data & MSR_IA32_RTIT_OUTPUT_BASE_MASK)
+ if (!pt_output_base_valid(vcpu, data))
return 1;
vmx->pt_desc.guest.output_base = data;
break;
--
2.28.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v3 4/5] KVM: x86: Move illegal GPA helper out of the MMU code
2020-09-24 19:42 [PATCH v3 0/5] KVM: VMX: Clean up RTIT MAXPHYADDR usage Sean Christopherson
` (2 preceding siblings ...)
2020-09-24 19:42 ` [PATCH v3 3/5] KVM: VMX: Replace MSR_IA32_RTIT_OUTPUT_BASE_MASK with helper function Sean Christopherson
@ 2020-09-24 19:42 ` Sean Christopherson
2020-09-24 19:42 ` [PATCH v3 5/5] KVM: VMX: Use "illegal GPA" helper for PT/RTIT output base check Sean Christopherson
2020-09-25 19:50 ` [PATCH v3 0/5] KVM: VMX: Clean up RTIT MAXPHYADDR usage Paolo Bonzini
5 siblings, 0 replies; 7+ messages in thread
From: Sean Christopherson @ 2020-09-24 19:42 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, kvm, linux-kernel
Rename kvm_mmu_is_illegal_gpa() to kvm_vcpu_is_illegal_gpa() and move it
to cpuid.h so that's it's colocated with cpuid_maxphyaddr(). The helper
is not MMU specific and will gain a user that is completely unrelated to
the MMU in a future patch.
No functional change intended.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/cpuid.h | 5 +++++
arch/x86/kvm/mmu.h | 5 -----
arch/x86/kvm/mmu/mmu.c | 2 +-
arch/x86/kvm/vmx/vmx.c | 2 +-
4 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index 3a923ae15f2f..1d2c4f2e4bb6 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -34,6 +34,11 @@ static inline int cpuid_maxphyaddr(struct kvm_vcpu *vcpu)
return vcpu->arch.maxphyaddr;
}
+static inline bool kvm_vcpu_is_illegal_gpa(struct kvm_vcpu *vcpu, gpa_t gpa)
+{
+ return (gpa >= BIT_ULL(cpuid_maxphyaddr(vcpu)));
+}
+
struct cpuid_reg {
u32 function;
u32 index;
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 5efc6081ca13..9c4a9c8e43d9 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -155,11 +155,6 @@ static inline bool is_write_protection(struct kvm_vcpu *vcpu)
return kvm_read_cr0_bits(vcpu, X86_CR0_WP);
}
-static inline bool kvm_mmu_is_illegal_gpa(struct kvm_vcpu *vcpu, gpa_t gpa)
-{
- return (gpa >= BIT_ULL(cpuid_maxphyaddr(vcpu)));
-}
-
/*
* Check if a given access (described through the I/D, W/R and U/S bits of a
* page fault error code pfec) causes a permission fault with the given PTE
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 76c5826e29a2..2e7251eec1f8 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -521,7 +521,7 @@ static gpa_t translate_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
struct x86_exception *exception)
{
/* Check if guest physical address doesn't exceed guest maximum */
- if (kvm_mmu_is_illegal_gpa(vcpu, gpa)) {
+ if (kvm_vcpu_is_illegal_gpa(vcpu, gpa)) {
exception->error_code |= PFERR_RSVD_MASK;
return UNMAPPED_GVA;
}
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 0d41faf63b57..7987de212057 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5307,7 +5307,7 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
* would also use advanced VM-exit information for EPT violations to
* reconstruct the page fault error code.
*/
- if (unlikely(kvm_mmu_is_illegal_gpa(vcpu, gpa)))
+ if (unlikely(kvm_vcpu_is_illegal_gpa(vcpu, gpa)))
return kvm_emulate_instruction(vcpu, 0);
return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
--
2.28.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v3 5/5] KVM: VMX: Use "illegal GPA" helper for PT/RTIT output base check
2020-09-24 19:42 [PATCH v3 0/5] KVM: VMX: Clean up RTIT MAXPHYADDR usage Sean Christopherson
` (3 preceding siblings ...)
2020-09-24 19:42 ` [PATCH v3 4/5] KVM: x86: Move illegal GPA helper out of the MMU code Sean Christopherson
@ 2020-09-24 19:42 ` Sean Christopherson
2020-09-25 19:50 ` [PATCH v3 0/5] KVM: VMX: Clean up RTIT MAXPHYADDR usage Paolo Bonzini
5 siblings, 0 replies; 7+ messages in thread
From: Sean Christopherson @ 2020-09-24 19:42 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, kvm, linux-kernel
Use kvm_vcpu_is_illegal_gpa() to check for a legal GPA when validating a
PT output base instead of open coding a clever, but difficult to read,
variant. Code readability is far more important than shaving a few uops
in a slow path.
No functional change intended.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/vmx/vmx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 7987de212057..8f1eb5dca794 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1037,7 +1037,7 @@ static inline bool pt_can_write_msr(struct vcpu_vmx *vmx)
static inline bool pt_output_base_valid(struct kvm_vcpu *vcpu, u64 base)
{
/* The base must be 128-byte aligned and a legal physical address. */
- return !(base & (~((1UL << cpuid_maxphyaddr(vcpu)) - 1) | 0x7f));
+ return !kvm_vcpu_is_illegal_gpa(vcpu, base) && !(base & 0x7f);
}
static inline void pt_load_msr(struct pt_ctx *ctx, u32 addr_range)
--
2.28.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH v3 0/5] KVM: VMX: Clean up RTIT MAXPHYADDR usage
2020-09-24 19:42 [PATCH v3 0/5] KVM: VMX: Clean up RTIT MAXPHYADDR usage Sean Christopherson
` (4 preceding siblings ...)
2020-09-24 19:42 ` [PATCH v3 5/5] KVM: VMX: Use "illegal GPA" helper for PT/RTIT output base check Sean Christopherson
@ 2020-09-25 19:50 ` Paolo Bonzini
5 siblings, 0 replies; 7+ messages in thread
From: Paolo Bonzini @ 2020-09-25 19:50 UTC (permalink / raw)
To: Sean Christopherson
Cc: Vitaly Kuznetsov, Wanpeng Li, Jim Mattson, Joerg Roedel, kvm,
linux-kernel
On 24/09/20 21:42, Sean Christopherson wrote:
> Stop using cpuid_query_maxphyaddr() for a random RTIT MSR check, unexport
> said function to discourage future use, and do additional related cleanup.
>
> Paolo, feel free to reorder/squash these as you see fit. Five patches
> feels more than a bit gratuitous, but every time I tried to squash things
> I ended up with changelogs that ran on and on...
>
> v2:
> - Rebased to kvm/queue, commit e1ba1a15af73 ("KVM: SVM: Enable INVPCID
> feature on AMD").
>
> Sean Christopherson (5):
> KVM: VMX: Use precomputed MAXPHYADDR for RTIT base MSR check
> KVM: x86: Unexport cpuid_query_maxphyaddr()
> KVM: VMX: Replace MSR_IA32_RTIT_OUTPUT_BASE_MASK with helper function
> KVM: x86: Move illegal GPA helper out of the MMU code
> KVM: VMX: Use "illegal GPA" helper for PT/RTIT output base check
>
> arch/x86/kvm/cpuid.c | 1 -
> arch/x86/kvm/cpuid.h | 5 +++++
> arch/x86/kvm/mmu.h | 5 -----
> arch/x86/kvm/mmu/mmu.c | 2 +-
> arch/x86/kvm/vmx/vmx.c | 13 ++++++++-----
> 5 files changed, 14 insertions(+), 12 deletions(-)
>
Queued, thanks.
Paolo
^ permalink raw reply [flat|nested] 7+ messages in thread