[PATCH v7 5/9] x86: spp: Introduce user-space SPP IOCTLs
From: Yang Weijiang
Date: Tue Nov 19 2019 - 03:48:09 EST
User application, e.g., QEMU or VMI, must initialize SPP
before gets/sets SPP subpages, the dynamic initialization is to
reduce the extra storage cost if the SPP feature is not not used.
Co-developed-by: He Chen <he.chen@xxxxxxxxxxxxxxx>
Signed-off-by: He Chen <he.chen@xxxxxxxxxxxxxxx>
Co-developed-by: Zhang Yi <yi.z.zhang@xxxxxxxxxxxxxxx>
Signed-off-by: Zhang Yi <yi.z.zhang@xxxxxxxxxxxxxxx>
Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 3 ++
arch/x86/kvm/vmx/spp.c | 54 +++++++++++++++++++++++++++++++++
arch/x86/kvm/vmx/spp.h | 5 +++
arch/x86/kvm/vmx/vmx.c | 8 +++++
arch/x86/kvm/x86.c | 49 ++++++++++++++++++++++++++++++
include/uapi/linux/kvm.h | 3 ++
6 files changed, 122 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index cc38670a0c45..3863eb3c0e6a 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1216,6 +1216,9 @@ struct kvm_x86_ops {
uint16_t (*nested_get_evmcs_version)(struct kvm_vcpu *vcpu);
bool (*need_emulation_on_page_fault)(struct kvm_vcpu *vcpu);
+
+ int (*init_spp)(struct kvm *kvm);
+ int (*flush_subpages)(struct kvm *kvm, struct kvm_subpage *spp_info);
};
struct kvm_arch_async_pf {
diff --git a/arch/x86/kvm/vmx/spp.c b/arch/x86/kvm/vmx/spp.c
index 964d31fe9426..b5327faf512e 100644
--- a/arch/x86/kvm/vmx/spp.c
+++ b/arch/x86/kvm/vmx/spp.c
@@ -538,3 +538,57 @@ inline u64 construct_spptp(unsigned long root_hpa)
}
EXPORT_SYMBOL_GPL(construct_spptp);
+int kvm_vm_ioctl_get_subpages(struct kvm *kvm,
+ struct kvm_subpage *spp_info)
+{
+ int ret;
+
+ mutex_lock(&kvm->slots_lock);
+ ret = kvm_spp_get_permission(kvm, spp_info);
+ mutex_unlock(&kvm->slots_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kvm_vm_ioctl_get_subpages);
+
+int kvm_vm_ioctl_set_subpages(struct kvm *kvm,
+ struct kvm_subpage *spp_info)
+{
+ int ret;
+
+ if (!kvm_x86_ops->flush_subpages)
+ return -EINVAL;
+
+ spin_lock(&kvm->mmu_lock);
+ ret = kvm_x86_ops->flush_subpages(kvm, spp_info);
+ spin_unlock(&kvm->mmu_lock);
+
+ if (ret < 0)
+ return ret;
+
+ mutex_lock(&kvm->slots_lock);
+ spin_lock(&kvm->mmu_lock);
+
+ ret = kvm_spp_set_permission(kvm, spp_info);
+
+ spin_unlock(&kvm->mmu_lock);
+ mutex_unlock(&kvm->slots_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kvm_vm_ioctl_set_subpages);
+
+int kvm_vm_ioctl_init_spp(struct kvm *kvm)
+{
+ int ret;
+
+ if (!kvm_x86_ops->init_spp)
+ return -ENODEV;
+
+ mutex_lock(&kvm->slots_lock);
+ ret = kvm_x86_ops->init_spp(kvm);
+ mutex_unlock(&kvm->slots_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kvm_vm_ioctl_init_spp);
diff --git a/arch/x86/kvm/vmx/spp.h b/arch/x86/kvm/vmx/spp.h
index 56b287ec15fd..ad13a35bfca2 100644
--- a/arch/x86/kvm/vmx/spp.h
+++ b/arch/x86/kvm/vmx/spp.h
@@ -6,6 +6,11 @@
bool is_spp_spte(struct kvm_mmu_page *sp);
inline u64 construct_spptp(unsigned long root_hpa);
+int kvm_vm_ioctl_get_subpages(struct kvm *kvm,
+ struct kvm_subpage *spp_info);
+int kvm_vm_ioctl_set_subpages(struct kvm *kvm,
+ struct kvm_subpage *spp_info);
+int kvm_vm_ioctl_init_spp(struct kvm *kvm);
int kvm_spp_setup_structure(struct kvm_vcpu *vcpu,
u32 access_map, gfn_t gfn);
int vmx_spp_flush_sppt(struct kvm *kvm, struct kvm_subpage *spp_info);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 0fcd02b531ef..af296a290173 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7596,6 +7596,11 @@ static __init int hardware_setup(void)
kvm_x86_ops->enable_log_dirty_pt_masked = NULL;
}
+ if (!spp_supported) {
+ kvm_x86_ops->flush_subpages = NULL;
+ kvm_x86_ops->init_spp = NULL;
+ }
+
if (!cpu_has_vmx_preemption_timer())
enable_preemption_timer = false;
@@ -7808,6 +7813,9 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
.nested_enable_evmcs = NULL,
.nested_get_evmcs_version = NULL,
.need_emulation_on_page_fault = vmx_need_emulation_on_page_fault,
+
+ .flush_subpages = vmx_spp_flush_sppt,
+ .init_spp = vmx_spp_init,
};
static void vmx_cleanup_l1d_flush(void)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 91602d310a3f..78605d75690e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -26,6 +26,7 @@
#include "cpuid.h"
#include "pmu.h"
#include "hyperv.h"
+#include "vmx/spp.h"
#include <linux/clocksource.h>
#include <linux/interrupt.h>
@@ -4977,6 +4978,54 @@ long kvm_arch_vm_ioctl(struct file *filp,
case KVM_SET_PMU_EVENT_FILTER:
r = kvm_vm_ioctl_set_pmu_event_filter(kvm, argp);
break;
+ case KVM_SUBPAGES_GET_ACCESS: {
+ struct kvm_subpage spp_info;
+
+ if (!kvm->arch.spp_active) {
+ r = -ENODEV;
+ goto out;
+ }
+
+ r = -EFAULT;
+ if (copy_from_user(&spp_info, argp, sizeof(spp_info)))
+ goto out;
+
+ r = -EINVAL;
+ if (spp_info.npages == 0 ||
+ spp_info.npages > SUBPAGE_MAX_BITMAP)
+ goto out;
+
+ r = kvm_vm_ioctl_get_subpages(kvm, &spp_info);
+ if (copy_to_user(argp, &spp_info, sizeof(spp_info))) {
+ r = -EFAULT;
+ goto out;
+ }
+ break;
+ }
+ case KVM_SUBPAGES_SET_ACCESS: {
+ struct kvm_subpage spp_info;
+
+ if (!kvm->arch.spp_active) {
+ r = -ENODEV;
+ goto out;
+ }
+
+ r = -EFAULT;
+ if (copy_from_user(&spp_info, argp, sizeof(spp_info)))
+ goto out;
+
+ r = -EINVAL;
+ if (spp_info.npages == 0 ||
+ spp_info.npages > SUBPAGE_MAX_BITMAP)
+ goto out;
+
+ r = kvm_vm_ioctl_set_subpages(kvm, &spp_info);
+ break;
+ }
+ case KVM_INIT_SPP: {
+ r = kvm_vm_ioctl_init_spp(kvm);
+ break;
+ }
default:
r = -ENOTTY;
}
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 9460830de536..700f0825336d 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1257,6 +1257,9 @@ struct kvm_vfio_spapr_tce {
struct kvm_userspace_memory_region)
#define KVM_SET_TSS_ADDR _IO(KVMIO, 0x47)
#define KVM_SET_IDENTITY_MAP_ADDR _IOW(KVMIO, 0x48, __u64)
+#define KVM_SUBPAGES_GET_ACCESS _IOR(KVMIO, 0x49, __u64)
+#define KVM_SUBPAGES_SET_ACCESS _IOW(KVMIO, 0x4a, __u64)
+#define KVM_INIT_SPP _IOW(KVMIO, 0x4b, __u64)
/* enable ucontrol for s390 */
struct kvm_s390_ucas_mapping {
--
2.17.2