[PATCH] Move translate_gpa() initialization for the nested context into init_kvm_nested_mmu()

[PATCH] Move translate_gpa() initialization for the nested context into init_kvm_nested_mmu()

[Zhihui Zhang]

This is the right place to set the function pointer. In addition, change function name
from translate_nested_gpa() to translate_gpa_nested() to match the naming convention of
other functions (e.g., paging64_gva_to_gpa_nested()).

Signed-off-by: Zhihui Zhang <zzhsuny@gmail.com>
---
 arch/x86/include/asm/kvm_host.h | 2 +-
 arch/x86/kvm/mmu.c              | 2 +-
 arch/x86/kvm/x86.c              | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ae5d783..a38be84 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -916,7 +916,7 @@ void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu);
 int kvm_mmu_load(struct kvm_vcpu *vcpu);
 void kvm_mmu_unload(struct kvm_vcpu *vcpu);
 void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu);
-gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access);
+gpa_t translate_gpa_nested(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access);
 gpa_t kvm_mmu_gva_to_gpa_read(struct kvm_vcpu *vcpu, gva_t gva,
 			      struct x86_exception *exception);
 gpa_t kvm_mmu_gva_to_gpa_fetch(struct kvm_vcpu *vcpu, gva_t gva,
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 40772ef..8bd6a5f 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3804,6 +3804,7 @@ static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu)
 	g_context->get_cr3           = get_cr3;
 	g_context->get_pdptr         = kvm_pdptr_read;
 	g_context->inject_page_fault = kvm_inject_page_fault;
+	g_context->translate_gpa     = translate_gpa_nested;
 
 	/*
 	 * Note that arch.mmu.gva_to_gpa translates l2_gva to l1_gpa. The
@@ -4230,7 +4231,6 @@ int kvm_mmu_create(struct kvm_vcpu *vcpu)
 	vcpu->arch.walk_mmu = &vcpu->arch.mmu;
 	vcpu->arch.mmu.root_hpa = INVALID_PAGE;
 	vcpu->arch.mmu.translate_gpa = translate_gpa;
-	vcpu->arch.nested_mmu.translate_gpa = translate_nested_gpa;
 
 	return alloc_mmu_pages(vcpu);
 }
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5d004da..f5cc306 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3938,7 +3938,7 @@ void kvm_get_segment(struct kvm_vcpu *vcpu,
 	kvm_x86_ops->get_segment(vcpu, var, seg);
 }
 
-gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access)
+gpa_t translate_gpa_nested(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access)
 {
 	gpa_t t_gpa;
 	struct x86_exception exception;
-- 
1.8.1.2

Re: [PATCH] Move translate_gpa() initialization for the nested context into init_kvm_nested_mmu()

[Marcelo Tosatti]

On Mon, Dec 30, 2013 at 08:22:21PM -0500, Zhihui Zhang wrote:
> This is the right place to set the function pointer. In addition, change function name
> from translate_nested_gpa() to translate_gpa_nested() to match the naming convention of
> other functions (e.g., paging64_gva_to_gpa_nested()).
> 
> Signed-off-by: Zhihui Zhang <zzhsuny@gmail.com>

Why is it the right place? The assignment was executed once per
VM-creation, now its executed once per kvm_mmu_reset_context
(which is a downside). Another downside is that 

  	vcpu->arch.mmu.translate_gpa = translate_gpa;
	vcpu->arch.nested_mmu.translate_gpa = translate_nested_gpa;

You lose this proximity.