[PATCH v2 12/12] KVM/nSVM: Use the new mapping API for mapping guest memory

KarimAllah Ahmed
2018-04-15T21:53:18Z

Use the new mapping API for mapping guest memory to avoid depending on
"struct page".

Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
---
arch/x86/kvm/svm.c | 97 +++++++++++++++++++++++++++---------------------------
1 file changed, 49 insertions(+), 48 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index b4ade8d..1706eab 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3026,32 +3026,6 @@ static inline bool nested_svm_nmi(struct vcpu_svm *svm)
return false;
}

-static void *nested_svm_map(struct vcpu_svm *svm, u64 gpa, struct page **_page)
-{
- struct page *page;
-
- might_sleep();
-
- page = kvm_vcpu_gfn_to_page(&svm->vcpu, gpa >> PAGE_SHIFT);
- if (is_error_page(page))
- goto error;
-
- *_page = page;
-
- return kmap(page);
-
-error:
- kvm_inject_gp(&svm->vcpu, 0);
-
- return NULL;
-}
-
-static void nested_svm_unmap(struct page *page)
-{
- kunmap(page);
- kvm_release_page_dirty(page);
-}
-
static int nested_svm_intercept_ioio(struct vcpu_svm *svm)
{
unsigned port, size, iopm_len;
@@ -3252,10 +3226,11 @@ static inline void copy_vmcb_control_area(struct vmcb *dst_vmcb, struct vmcb *fr

static int nested_svm_vmexit(struct vcpu_svm *svm)
{
+ int rc;
struct vmcb *nested_vmcb;
struct vmcb *hsave = svm->nested.hsave;
struct vmcb *vmcb = svm->vmcb;
- struct page *page;
+ struct kvm_host_map map;

trace_kvm_nested_vmexit_inject(vmcb->control.exit_code,
vmcb->control.exit_info_1,
@@ -3264,9 +3239,14 @@ static int nested_svm_vmexit(struct vcpu_svm *svm)
vmcb->control.exit_int_info_err,
KVM_ISA_SVM);

- nested_vmcb = nested_svm_map(svm, svm->nested.vmcb, &page);
- if (!nested_vmcb)
+ rc = kvm_vcpu_map(&svm->vcpu, gfn_to_gpa(svm->nested.vmcb), &map);
+ if (rc) {
+ if (rc == -EINVAL)
+ kvm_inject_gp(&svm->vcpu, 0);
return 1;
+ }
+
+ nested_vmcb = map.hva;

/* Exit Guest-Mode */
leave_guest_mode(&svm->vcpu);
@@ -3365,7 +3345,7 @@ static int nested_svm_vmexit(struct vcpu_svm *svm)

mark_all_dirty(svm->vmcb);

- nested_svm_unmap(page);
+ kvm_vcpu_unmap(&map);

nested_svm_uninit_mmu_context(&svm->vcpu);
kvm_mmu_reset_context(&svm->vcpu);
@@ -3423,7 +3403,7 @@ static bool nested_vmcb_checks(struct vmcb *vmcb)
}

static void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
- struct vmcb *nested_vmcb, struct page *page)
+ struct vmcb *nested_vmcb, struct kvm_host_map *map)
{
if (kvm_get_rflags(&svm->vcpu) & X86_EFLAGS_IF)
svm->vcpu.arch.hflags |= HF_HIF_MASK;
@@ -3503,7 +3483,7 @@ static void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
svm->vmcb->control.event_inj = nested_vmcb->control.event_inj;
svm->vmcb->control.event_inj_err = nested_vmcb->control.event_inj_err;

- nested_svm_unmap(page);
+ kvm_vcpu_unmap(map);

/* Enter Guest-Mode */
enter_guest_mode(&svm->vcpu);
@@ -3523,17 +3503,23 @@ static void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,

static bool nested_svm_vmrun(struct vcpu_svm *svm)
{
+ int rc;
struct vmcb *nested_vmcb;
struct vmcb *hsave = svm->nested.hsave;
struct vmcb *vmcb = svm->vmcb;
- struct page *page;
+ struct kvm_host_map map;
u64 vmcb_gpa;

vmcb_gpa = svm->vmcb->save.rax;

- nested_vmcb = nested_svm_map(svm, svm->vmcb->save.rax, &page);
- if (!nested_vmcb)
+ rc = kvm_vcpu_map(&svm->vcpu, gfn_to_gpa(vmcb_gpa), &map);
+ if (rc) {
+ if (rc == -EINVAL)
+ kvm_inject_gp(&svm->vcpu, 0);
return false;
+ }
+
+ nested_vmcb = map.hva;

if (!nested_vmcb_checks(nested_vmcb)) {
nested_vmcb->control.exit_code = SVM_EXIT_ERR;
@@ -3541,7 +3527,7 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
nested_vmcb->control.exit_info_1 = 0;
nested_vmcb->control.exit_info_2 = 0;

- nested_svm_unmap(page);
+ kvm_vcpu_unmap(&map);

return false;
}
@@ -3585,7 +3571,7 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)

copy_vmcb_control_area(hsave, vmcb);

- enter_svm_guest_mode(svm, vmcb_gpa, nested_vmcb, page);
+ enter_svm_guest_mode(svm, vmcb_gpa, nested_vmcb, &map);

return true;
}
@@ -3609,21 +3595,26 @@ static void nested_svm_vmloadsave(struct vmcb *from_vmcb, struct vmcb *to_vmcb)
static int vmload_interception(struct vcpu_svm *svm)
{
struct vmcb *nested_vmcb;
- struct page *page;
+ struct kvm_host_map map;
int ret;

if (nested_svm_check_permissions(svm))
return 1;

- nested_vmcb = nested_svm_map(svm, svm->vmcb->save.rax, &page);
- if (!nested_vmcb)
+ ret = kvm_vcpu_map(&svm->vcpu, gpa_to_gfn(svm->vmcb->save.rax), &map);
+ if (ret) {
+ if (ret == -EINVAL)
+ kvm_inject_gp(&svm->vcpu, 0);
return 1;
+ }
+
+ nested_vmcb = map.hva;

svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
ret = kvm_skip_emulated_instruction(&svm->vcpu);

nested_svm_vmloadsave(nested_vmcb, svm->vmcb);
- nested_svm_unmap(page);
+ kvm_vcpu_unmap(&map);

return ret;
}
@@ -3631,21 +3622,26 @@ static int vmload_interception(struct vcpu_svm *svm)
static int vmsave_interception(struct vcpu_svm *svm)
{
struct vmcb *nested_vmcb;
- struct page *page;
+ struct kvm_host_map map;
int ret;

if (nested_svm_check_permissions(svm))
return 1;

- nested_vmcb = nested_svm_map(svm, svm->vmcb->save.rax, &page);
- if (!nested_vmcb)
+ ret = kvm_vcpu_map(&svm->vcpu, gpa_to_gfn(svm->vmcb->save.rax), &map);
+ if (ret) {
+ if (ret == -EINVAL)
+ kvm_inject_gp(&svm->vcpu, 0);
return 1;
+ }
+
+ nested_vmcb = map.hva;

svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
ret = kvm_skip_emulated_instruction(&svm->vcpu);

nested_svm_vmloadsave(svm->vmcb, nested_vmcb);
- nested_svm_unmap(page);
+ kvm_vcpu_unmap(&map);

return ret;
}
@@ -6152,7 +6148,7 @@ static int svm_pre_leave_smm(struct kvm_vcpu *vcpu, u64 smbase)
{
struct vcpu_svm *svm = to_svm(vcpu);
struct vmcb *nested_vmcb;
- struct page *page;
+ struct kvm_host_map map;
struct {
u64 guest;
u64 vmcb;
@@ -6166,11 +6162,16 @@ static int svm_pre_leave_smm(struct kvm_vcpu *vcpu, u64 smbase)

if (svm_state_save.guest) {
vcpu->arch.hflags &= ~HF_SMM_MASK;
- nested_vmcb = nested_svm_map(svm, svm_state_save.vmcb, &page);
+ if (kvm_vcpu_map(&svm->vcpu, gpa_to_gfn(svm_state_save.vmcb), &map) == -EINVAL)
+ kvm_inject_gp(&svm->vcpu, 0);
+
+ nested_vmcb = map.hva;
+
if (nested_vmcb)
- enter_svm_guest_mode(svm, svm_state_save.vmcb, nested_vmcb, page);
+ enter_svm_guest_mode(svm, svm_state_save.vmcb, nested_vmcb, &map);
else
ret = 1;
+
vcpu->arch.hflags |= HF_SMM_MASK;
}
return ret;
--
2.7.4