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Message-ID: <1578408399-20092-3-git-send-email-weiqi4@huawei.com>
Date: Tue, 7 Jan 2020 22:46:39 +0800
From: weiqi <weiqi4@...wei.com>
To: <alexander.h.duyck@...ux.intel.com>, <alex.williamson@...hat.com>
CC: <kvm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<pbonzini@...hat.com>, <x86@...nel.org>, wei qi <weiqi4@...wei.com>
Subject: [PATCH 2/2] KVM: add support for page hinting
From: wei qi <weiqi4@...wei.com>
add support for page hinting.
Signed-off-by: wei qi <weiqi4@...wei.com>
---
arch/x86/kvm/mmu/mmu.c | 79 +++++++++++++++++++++++++++++++++++++++
arch/x86/kvm/x86.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/kvm_host.h | 41 +++++++++++++++++++++
include/uapi/linux/kvm.h | 7 ++++
virt/kvm/vfio.c | 11 ------
5 files changed, 223 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 6f92b40..0cf2584 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4259,6 +4259,71 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
return kvm_mtrr_check_gfn_range_consistency(vcpu, gfn, page_num);
}
+#include <linux/vfio.h>
+static void kvm_vfio_mmap_range(struct kvm_vcpu *vcpu, struct kvm_device *tmp,
+ gfn_t gfn, kvm_pfn_t pfn)
+{
+ struct kvm_vfio *kv = tmp->private;
+ struct kvm_vfio_group *kvg;
+
+ list_for_each_entry(kvg, &kv->group_list, node) {
+ struct vfio_group *group = kvg->vfio_group;
+ struct vfio_device *it, *device = NULL;
+
+ list_for_each_entry(it, &group->device_list, group_next) {
+ int flags;
+ unsigned long page_size;
+ struct kvm_memory_slot *memslot;
+ int size;
+ unsigned long old_pfn = 0;
+ gfn_t gfn_base;
+ kvm_pfn_t pfn_base;
+
+ device = it;
+ memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
+ page_size = kvm_host_page_size(vcpu->kvm, gfn);
+
+ /* only discard free pages, just check 2M hugetlb */
+ if (page_size >> PAGE_SHIFT != 512)
+ return;
+
+ gfn_base = ((gfn << PAGE_SHIFT) & (~(page_size - 1)))
+ >> PAGE_SHIFT;
+ pfn_base = ((pfn << PAGE_SHIFT) & (~(page_size - 1)))
+ >> PAGE_SHIFT;
+
+ while ((gfn << PAGE_SHIFT) & (page_size - 1))
+ page_size >>= 1;
+
+ while (__gfn_to_hva_memslot(memslot, gfn) &
+ (page_size - 1))
+ page_size >>= 1;
+
+ size = vfio_dma_find(device->dev, gfn_base,
+ page_size >> PAGE_SHIFT, &old_pfn);
+ if (!size) {
+ pr_err("%s:not find dma: gfn: %llx, size: %lu.\n",
+ __func__, gfn_base,
+ page_size >> PAGE_SHIFT);
+ return;
+ }
+ if (!old_pfn)
+ pr_err("%s: not find pfn: gfn: %llx, size: %lu.\n",
+ __func__, gfn_base,
+ page_size >> PAGE_SHIFT);
+
+ if (pfn_base == old_pfn)
+ return;
+
+ flags = IOMMU_READ;
+ if (!(memslot->flags & KVM_MEM_READONLY))
+ flags |= IOMMU_WRITE;
+ vfio_mmap_pages(device->dev, gfn,
+ page_size, flags, pfn);
+ }
+ }
+}
+
static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code,
bool prefault)
{
@@ -4317,6 +4382,20 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code,
prefault, lpage_disallowed);
out_unlock:
spin_unlock(&vcpu->kvm->mmu_lock);
+
+ if (!is_noslot_pfn(pfn) && gfn) {
+ struct kvm_device *tmp;
+
+ list_for_each_entry(tmp, &vcpu->kvm->devices, vm_node) {
+ if (tmp->ops && tmp->ops->name &&
+ (!strcmp(tmp->ops->name, "kvm-vfio"))) {
+ spin_lock(&vcpu->kvm->discard_lock);
+ kvm_vfio_mmap_range(vcpu, tmp, gfn, pfn);
+ spin_unlock(&vcpu->kvm->discard_lock);
+ }
+ }
+ }
+
kvm_release_pfn_clean(pfn);
return r;
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cf91713..264c65e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4837,6 +4837,92 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
return r;
}
+#include <linux/vfio.h>
+static void kvm_vfio_ummap_range(struct kvm *kvm, struct kvm_device *tmp,
+ gfn_t gfn, int npages, unsigned long hva)
+{
+ struct kvm_vfio *kv = tmp->private;
+ struct kvm_vfio_group *kvg;
+
+ list_for_each_entry(kvg, &kv->group_list, node) {
+ struct vfio_group *group = kvg->vfio_group;
+ struct vfio_device *it, *device = NULL;
+
+ list_for_each_entry(it, &group->device_list, group_next) {
+ unsigned long page_size, page_size_base;
+ unsigned long addr;
+ int size;
+ unsigned long old_pfn = 0;
+ int ret = 0;
+ size_t unmapped = npages;
+ gfn_t iova_gfn = gfn;
+ unsigned long iova_hva = hva;
+
+ device = it;
+ while (unmapped) {
+ addr = gfn_to_hva(kvm, iova_gfn);
+ page_size_base = page_size =
+ kvm_host_page_size(kvm,
+ iova_gfn);
+
+ if (addr != iova_hva)
+ return;
+
+ while ((iova_gfn << PAGE_SHIFT) &
+ (page_size - 1))
+ page_size >>= 1;
+
+ while (addr & (page_size - 1))
+ page_size >>= 1;
+
+ if (page_size_base != page_size)
+ return;
+
+ size = vfio_dma_find(device->dev, iova_gfn,
+ page_size >> PAGE_SHIFT,
+ &old_pfn);
+ if (!size)
+ return;
+
+ if (!old_pfn)
+ return;
+
+ ret = vfio_munmap_pages(device->dev,
+ iova_gfn, page_size);
+ unmapped -= page_size >> PAGE_SHIFT;
+ iova_hva += page_size;
+ iova_gfn += page_size >> PAGE_SHIFT;
+ }
+ }
+ }
+}
+
+
+static int kvm_vm_ioctl_discard_range(struct kvm *kvm,
+ struct kvm_discard_msg *msg)
+{
+ gfn_t gfn, end_gfn;
+ int idx;
+ struct kvm_device *tmp;
+ unsigned long hva = msg->iov_base;
+ int npages = msg->iov_len >> PAGE_SHIFT;
+
+ gfn = gpa_to_gfn(msg->in_addr);
+ end_gfn = gpa_to_gfn(msg->in_addr + msg->iov_len);
+
+ idx = srcu_read_lock(&kvm->srcu);
+
+ list_for_each_entry(tmp, &kvm->devices, vm_node) {
+ if (tmp->ops->name && (!strcmp(tmp->ops->name, "kvm-vfio"))) {
+ spin_lock(&kvm->discard_lock);
+ kvm_vfio_ummap_range(kvm, tmp, gfn, npages, hva);
+ spin_unlock(&kvm->discard_lock);
+ }
+ }
+ srcu_read_unlock(&kvm->srcu, idx);
+ return 0;
+}
+
long kvm_arch_vm_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
@@ -5134,6 +5220,16 @@ 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_DISCARD_RANGE: {
+ struct kvm_discard_msg discard_msg;
+
+ r = -EFAULT;
+ if (copy_from_user(&discard_msg, argp, sizeof(discard_msg)))
+ goto out;
+
+ r = kvm_vm_ioctl_discard_range(kvm, &discard_msg);
+ break;
+ }
default:
r = -ENOTTY;
}
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 538c25e..6667e6b 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -442,6 +442,7 @@ struct kvm_memslots {
struct kvm {
spinlock_t mmu_lock;
+ spinlock_t discard_lock;
struct mutex slots_lock;
struct mm_struct *mm; /* userspace tied to this vm */
struct kvm_memslots __rcu *memslots[KVM_ADDRESS_SPACE_NUM];
@@ -502,6 +503,46 @@ struct kvm {
struct srcu_struct irq_srcu;
pid_t userspace_pid;
};
+struct vfio_device {
+ struct kref kref;
+ struct device *dev;
+ const struct vfio_device_ops *ops;
+ struct vfio_group *group;
+ struct list_head group_next;
+ void *device_data;
+};
+
+struct vfio_group {
+ struct kref kref;
+ int minor;
+ atomic_t container_users;
+ struct iommu_group *iommu_group;
+ struct vfio_container *container;
+ struct list_head device_list;
+ struct mutex device_lock;
+ struct device *dev;
+ struct notifier_block nb;
+ struct list_head vfio_next;
+ struct list_head container_next;
+ struct list_head unbound_list;
+ struct mutex unbound_lock;
+ atomic_t opened;
+ wait_queue_head_t container_q;
+ bool noiommu;
+ struct kvm *kvm;
+ struct blocking_notifier_head notifier;
+};
+
+struct kvm_vfio_group {
+ struct list_head node;
+ struct vfio_group *vfio_group;
+};
+
+struct kvm_vfio {
+ struct list_head group_list;
+ struct mutex lock;
+ bool noncoherent;
+};
#define kvm_err(fmt, ...) \
pr_err("kvm [%i]: " fmt, task_pid_nr(current), ## __VA_ARGS__)
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index f0a16b4..53331fe 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1264,6 +1264,13 @@ 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)
+struct kvm_discard_msg {
+ __u64 iov_len;
+ __u64 iov_base;
+ __u64 in_addr;
+};
+#define KVM_DISCARD_RANGE _IOW(KVMIO, 0x49, struct kvm_discard_msg)
+
/* enable ucontrol for s390 */
struct kvm_s390_ucas_mapping {
diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index 8fcbc50..f6dc61e 100644
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -21,17 +21,6 @@
#include <asm/kvm_ppc.h>
#endif
-struct kvm_vfio_group {
- struct list_head node;
- struct vfio_group *vfio_group;
-};
-
-struct kvm_vfio {
- struct list_head group_list;
- struct mutex lock;
- bool noncoherent;
-};
-
static struct vfio_group *kvm_vfio_group_get_external_user(struct file *filep)
{
struct vfio_group *vfio_group;
--
1.8.3.1
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