diff mbox series

[04/21] KVM: VMX: Split out guts of EPT violation to common/exposed function

Message ID 20240904030751.117579-5-rick.p.edgecombe@intel.com (mailing list archive)
State New, archived
Headers show
Series TDX MMU Part 2 | expand

Commit Message

Rick Edgecombe Sept. 4, 2024, 3:07 a.m. UTC 
From: Sean Christopherson <sean.j.christopherson@intel.com>

The difference of TDX EPT violation is how to retrieve information, GPA,
and exit qualification.  To share the code to handle EPT violation, split
out the guts of EPT violation handler so that VMX/TDX exit handler can call
it after retrieving GPA and exit qualification.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
---
 arch/x86/kvm/vmx/common.h | 34 ++++++++++++++++++++++++++++++++++
 arch/x86/kvm/vmx/vmx.c    | 25 +++----------------------
 2 files changed, 37 insertions(+), 22 deletions(-)
 create mode 100644 arch/x86/kvm/vmx/common.h

Comments

Paolo Bonzini Sept. 9, 2024, 1:57 p.m. UTC | #1 
On 9/4/24 05:07, Rick Edgecombe wrote:
> From: Sean Christopherson <sean.j.christopherson@intel.com>
> 
> The difference of TDX EPT violation is how to retrieve information, GPA,
> and exit qualification.  To share the code to handle EPT violation, split
> out the guts of EPT violation handler so that VMX/TDX exit handler can call
> it after retrieving GPA and exit qualification.

Already has my RB but, for what it's worth, I'm not sure it's necessary 
to put this in a header as opposed to main.c.  Otherwise no comments, as 
there isn't much going on here.

Paolo
Sean Christopherson Sept. 9, 2024, 4:07 p.m. UTC | #2 
On Tue, Sep 03, 2024, Rick Edgecombe wrote:
> +static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa,
> +					     unsigned long exit_qualification)
> +{
> +	u64 error_code;
> +
> +	/* Is it a read fault? */
> +	error_code = (exit_qualification & EPT_VIOLATION_ACC_READ)
> +		     ? PFERR_USER_MASK : 0;
> +	/* Is it a write fault? */
> +	error_code |= (exit_qualification & EPT_VIOLATION_ACC_WRITE)
> +		      ? PFERR_WRITE_MASK : 0;
> +	/* Is it a fetch fault? */
> +	error_code |= (exit_qualification & EPT_VIOLATION_ACC_INSTR)
> +		      ? PFERR_FETCH_MASK : 0;
> +	/* ept page table entry is present? */
> +	error_code |= (exit_qualification & EPT_VIOLATION_RWX_MASK)
> +		      ? PFERR_PRESENT_MASK : 0;
> +
> +	if (error_code & EPT_VIOLATION_GVA_IS_VALID)
> +		error_code |= (exit_qualification & EPT_VIOLATION_GVA_TRANSLATED) ?
> +			      PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
> +
> +	return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
> +}
> +
> +#endif /* __KVM_X86_VMX_COMMON_H */
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 5e7b5732f35d..ade7666febe9 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -53,6 +53,7 @@
>  #include <trace/events/ipi.h>
>  
>  #include "capabilities.h"
> +#include "common.h"
>  #include "cpuid.h"
>  #include "hyperv.h"
>  #include "kvm_onhyperv.h"
> @@ -5771,11 +5772,8 @@ static int handle_task_switch(struct kvm_vcpu *vcpu)
>  
>  static int handle_ept_violation(struct kvm_vcpu *vcpu)
>  {
> -	unsigned long exit_qualification;
> +	unsigned long exit_qualification = vmx_get_exit_qual(vcpu);
>  	gpa_t gpa;
> -	u64 error_code;
> -
> -	exit_qualification = vmx_get_exit_qual(vcpu);
>  
>  	/*
>  	 * EPT violation happened while executing iret from NMI,
> @@ -5791,23 +5789,6 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
>  	gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
>  	trace_kvm_page_fault(vcpu, gpa, exit_qualification);
>  
> -	/* Is it a read fault? */
> -	error_code = (exit_qualification & EPT_VIOLATION_ACC_READ)
> -		     ? PFERR_USER_MASK : 0;
> -	/* Is it a write fault? */
> -	error_code |= (exit_qualification & EPT_VIOLATION_ACC_WRITE)
> -		      ? PFERR_WRITE_MASK : 0;
> -	/* Is it a fetch fault? */
> -	error_code |= (exit_qualification & EPT_VIOLATION_ACC_INSTR)
> -		      ? PFERR_FETCH_MASK : 0;
> -	/* ept page table entry is present? */
> -	error_code |= (exit_qualification & EPT_VIOLATION_RWX_MASK)
> -		      ? PFERR_PRESENT_MASK : 0;
> -
> -	if (error_code & EPT_VIOLATION_GVA_IS_VALID)
> -		error_code |= (exit_qualification & EPT_VIOLATION_GVA_TRANSLATED) ?
> -			      PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
> -

Paolo, are you planning on queueing these for 6.12, or for a later kernel?  I ask
because this will conflict with a bug fix[*] that I am planning on taking through
kvm-x86/mmu.  If you anticipate merging these in 6.12, then it'd probably be best
for you to grab that one patch directly, as I don't think it has semantic conflicts
with anything else in that series.

[*] https://lore.kernel.org/all/20240831001538.336683-2-seanjc@google.com
Paolo Bonzini Sept. 10, 2024, 7:36 a.m. UTC | #3 
On 9/9/24 18:07, Sean Christopherson wrote:
> Paolo, are you planning on queueing these for 6.12, or for a later kernel?  I ask
> because this will conflict with a bug fix[*] that I am planning on taking through
> kvm-x86/mmu.  If you anticipate merging these in 6.12, then it'd probably be best
> for you to grab that one patch directly, as I don't think it has semantic conflicts
> with anything else in that series.
> 
> [*]https://lore.kernel.org/all/20240831001538.336683-2-seanjc@google.com

No, this one is independent of TDX but the patches need not be rushed 
into 6.12.

Paolo
diff mbox series

Patch

diff --git a/arch/x86/kvm/vmx/common.h b/arch/x86/kvm/vmx/common.h
new file mode 100644
index 000000000000..78ae39b6cdcd
--- /dev/null
+++ b/arch/x86/kvm/vmx/common.h
@@ -0,0 +1,34 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __KVM_X86_VMX_COMMON_H
+#define __KVM_X86_VMX_COMMON_H
+
+#include <linux/kvm_host.h>
+
+#include "mmu.h"
+
+static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa,
+					     unsigned long exit_qualification)
+{
+	u64 error_code;
+
+	/* Is it a read fault? */
+	error_code = (exit_qualification & EPT_VIOLATION_ACC_READ)
+		     ? PFERR_USER_MASK : 0;
+	/* Is it a write fault? */
+	error_code |= (exit_qualification & EPT_VIOLATION_ACC_WRITE)
+		      ? PFERR_WRITE_MASK : 0;
+	/* Is it a fetch fault? */
+	error_code |= (exit_qualification & EPT_VIOLATION_ACC_INSTR)
+		      ? PFERR_FETCH_MASK : 0;
+	/* ept page table entry is present? */
+	error_code |= (exit_qualification & EPT_VIOLATION_RWX_MASK)
+		      ? PFERR_PRESENT_MASK : 0;
+
+	if (error_code & EPT_VIOLATION_GVA_IS_VALID)
+		error_code |= (exit_qualification & EPT_VIOLATION_GVA_TRANSLATED) ?
+			      PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
+
+	return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
+}
+
+#endif /* __KVM_X86_VMX_COMMON_H */
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5e7b5732f35d..ade7666febe9 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -53,6 +53,7 @@ 
 #include <trace/events/ipi.h>
 
 #include "capabilities.h"
+#include "common.h"
 #include "cpuid.h"
 #include "hyperv.h"
 #include "kvm_onhyperv.h"
@@ -5771,11 +5772,8 @@  static int handle_task_switch(struct kvm_vcpu *vcpu)
 
 static int handle_ept_violation(struct kvm_vcpu *vcpu)
 {
-	unsigned long exit_qualification;
+	unsigned long exit_qualification = vmx_get_exit_qual(vcpu);
 	gpa_t gpa;
-	u64 error_code;
-
-	exit_qualification = vmx_get_exit_qual(vcpu);
 
 	/*
 	 * EPT violation happened while executing iret from NMI,
@@ -5791,23 +5789,6 @@  static int handle_ept_violation(struct kvm_vcpu *vcpu)
 	gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
 	trace_kvm_page_fault(vcpu, gpa, exit_qualification);
 
-	/* Is it a read fault? */
-	error_code = (exit_qualification & EPT_VIOLATION_ACC_READ)
-		     ? PFERR_USER_MASK : 0;
-	/* Is it a write fault? */
-	error_code |= (exit_qualification & EPT_VIOLATION_ACC_WRITE)
-		      ? PFERR_WRITE_MASK : 0;
-	/* Is it a fetch fault? */
-	error_code |= (exit_qualification & EPT_VIOLATION_ACC_INSTR)
-		      ? PFERR_FETCH_MASK : 0;
-	/* ept page table entry is present? */
-	error_code |= (exit_qualification & EPT_VIOLATION_RWX_MASK)
-		      ? PFERR_PRESENT_MASK : 0;
-
-	if (error_code & EPT_VIOLATION_GVA_IS_VALID)
-		error_code |= (exit_qualification & EPT_VIOLATION_GVA_TRANSLATED) ?
-			      PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
-
 	/*
 	 * Check that the GPA doesn't exceed physical memory limits, as that is
 	 * a guest page fault.  We have to emulate the instruction here, because
@@ -5819,7 +5800,7 @@  static int handle_ept_violation(struct kvm_vcpu *vcpu)
 	if (unlikely(allow_smaller_maxphyaddr && !kvm_vcpu_is_legal_gpa(vcpu, gpa)))
 		return kvm_emulate_instruction(vcpu, 0);
 
-	return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
+	return __vmx_handle_ept_violation(vcpu, gpa, exit_qualification);
 }
 
 static int handle_ept_misconfig(struct kvm_vcpu *vcpu)