On 2/3/21 6:38 PM, Ashish Kalra wrote:
From: Brijesh Singh <brijesh.singh@xxxxxxx>
This hypercall is used by the SEV guest to notify a change in the page
encryption status to the hypervisor. The hypercall should be invoked
only when the encryption attribute is changed from encrypted -> decrypted
and vice versa. By default all guest pages are considered encrypted.
The patch introduces a new shared pages list implemented as a
sorted linked list to track the shared/unencrypted regions marked by the
guest hypercall.
...
+
+ if (enc) {
+ ret = remove_shared_region(gfn_start, gfn_end,
+ &sev->shared_pages_list);
+ if (ret != -ENOMEM)
+ sev->shared_pages_list_count += ret;
+ } else {
+ ret = add_shared_region(gfn_start, gfn_end,
+ &sev->shared_pages_list);
+ if (ret > 0)
+ sev->shared_pages_list_count++;
+ }
I would move the shared_pages_list_count updates into the add/remove
functions and then just return 0 or a -EXXXX error code from those
functions. It seems simpler than "adding" ret or checking for a greater
than 0 return code.
Thanks,
Tom
+
+ mutex_unlock(&kvm->lock);
+ return ret;
+}
+
int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
{
struct kvm_sev_cmd sev_cmd;
@@ -1693,6 +1842,7 @@ void sev_vm_destroy(struct kvm *kvm)
sev_unbind_asid(kvm, sev->handle);
sev_asid_free(sev->asid);
+ sev->shared_pages_list_count = 0;
}
void __init sev_hardware_setup(void)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index f923e14e87df..bb249ec625fc 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4536,6 +4536,8 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.complete_emulated_msr = svm_complete_emulated_msr,
.vcpu_deliver_sipi_vector = svm_vcpu_deliver_sipi_vector,
+
+ .page_enc_status_hc = svm_page_enc_status_hc,
};
static struct kvm_x86_init_ops svm_init_ops __initdata = {
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 0fe874ae5498..6437c1fa1f24 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -79,6 +79,9 @@ struct kvm_sev_info {
unsigned long pages_locked; /* Number of pages locked */
struct list_head regions_list; /* List of registered regions */
u64 ap_jump_table; /* SEV-ES AP Jump Table address */
+ /* List and count of shared pages */
+ int shared_pages_list_count;
+ struct list_head shared_pages_list;
};
struct kvm_svm {
@@ -472,6 +475,8 @@ int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
bool has_error_code, u32 error_code);
int nested_svm_exit_special(struct vcpu_svm *svm);
void sync_nested_vmcb_control(struct vcpu_svm *svm);
+int svm_page_enc_status_hc(struct kvm *kvm, unsigned long gpa,
+ unsigned long npages, unsigned long enc);
extern struct kvm_x86_nested_ops svm_nested_ops;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index cc60b1fc3ee7..bcbf53851612 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7705,6 +7705,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
.can_emulate_instruction = vmx_can_emulate_instruction,
.apic_init_signal_blocked = vmx_apic_init_signal_blocked,
.migrate_timers = vmx_migrate_timers,
+ .page_enc_status_hc = NULL,
.msr_filter_changed = vmx_msr_filter_changed,
.complete_emulated_msr = kvm_complete_insn_gp,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 76bce832cade..2f17f0f9ace7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8162,6 +8162,12 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
kvm_sched_yield(vcpu->kvm, a0);
ret = 0;
break;
+ case KVM_HC_PAGE_ENC_STATUS:
+ ret = -KVM_ENOSYS;
+ if (kvm_x86_ops.page_enc_status_hc)
+ ret = kvm_x86_ops.page_enc_status_hc(vcpu->kvm,
+ a0, a1, a2);
+ break;
default:
ret = -KVM_ENOSYS;
break;
diff --git a/include/uapi/linux/kvm_para.h b/include/uapi/linux/kvm_para.h
index 8b86609849b9..847b83b75dc8 100644
--- a/include/uapi/linux/kvm_para.h
+++ b/include/uapi/linux/kvm_para.h
@@ -29,6 +29,7 @@
#define KVM_HC_CLOCK_PAIRING 9
#define KVM_HC_SEND_IPI 10
#define KVM_HC_SCHED_YIELD 11
+#define KVM_HC_PAGE_ENC_STATUS 12
/*
* hypercalls use architecture specific
