From: isaku.yamahata@intel.com
To: kvm@vger.kernel.org
Cc: isaku.yamahata@intel.com, isaku.yamahata@gmail.com,
linux-kernel@vger.kernel.org,
Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Michael Roth <michael.roth@amd.com>,
David Matlack <dmatlack@google.com>,
Federico Parola <federico.parola@polito.it>
Subject: [RFC PATCH 2/8] KVM: Add KVM_MAP_MEMORY vcpu ioctl to pre-populate guest memory
Date: Fri, 1 Mar 2024 09:28:44 -0800 [thread overview]
Message-ID: <012b59708114ba121735769de94756fa5af3204d.1709288671.git.isaku.yamahata@intel.com> (raw)
In-Reply-To: <cover.1709288671.git.isaku.yamahata@intel.com>
From: Isaku Yamahata <isaku.yamahata@intel.com>
Add new ioctl KVM_MAP_MEMORY in the kvm common code. It iterates on the
memory range and call arch specific function. Add stub function as weak
symbol.
[1] https://lore.kernel.org/kvm/Zbrj5WKVgMsUFDtb@google.com/
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
include/linux/kvm_host.h | 4 +++
include/uapi/linux/kvm.h | 15 ++++++++
virt/kvm/kvm_main.c | 74 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 93 insertions(+)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 9807ea98b568..afbed288d625 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -2445,4 +2445,8 @@ static inline int kvm_gmem_get_pfn(struct kvm *kvm,
}
#endif /* CONFIG_KVM_PRIVATE_MEM */
+int kvm_arch_vcpu_pre_map_memory(struct kvm_vcpu *vcpu);
+int kvm_arch_vcpu_map_memory(struct kvm_vcpu *vcpu,
+ struct kvm_memory_mapping *mapping);
+
#endif
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 2190adbe3002..f5d6b481244f 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -917,6 +917,7 @@ struct kvm_enable_cap {
#define KVM_CAP_MEMORY_ATTRIBUTES 233
#define KVM_CAP_GUEST_MEMFD 234
#define KVM_CAP_VM_TYPES 235
+#define KVM_CAP_MAP_MEMORY 236
struct kvm_irq_routing_irqchip {
__u32 irqchip;
@@ -1548,4 +1549,18 @@ struct kvm_create_guest_memfd {
__u64 reserved[6];
};
+#define KVM_MAP_MEMORY _IOWR(KVMIO, 0xd5, struct kvm_memory_mapping)
+
+#define KVM_MEMORY_MAPPING_FLAG_WRITE _BITULL(0)
+#define KVM_MEMORY_MAPPING_FLAG_EXEC _BITULL(1)
+#define KVM_MEMORY_MAPPING_FLAG_USER _BITULL(2)
+#define KVM_MEMORY_MAPPING_FLAG_PRIVATE _BITULL(3)
+
+struct kvm_memory_mapping {
+ __u64 base_gfn;
+ __u64 nr_pages;
+ __u64 flags;
+ __u64 source;
+};
+
#endif /* __LINUX_KVM_H */
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d1fd9cb5d037..d77c9b79d76b 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4419,6 +4419,69 @@ static int kvm_vcpu_ioctl_get_stats_fd(struct kvm_vcpu *vcpu)
return fd;
}
+__weak int kvm_arch_vcpu_pre_map_memory(struct kvm_vcpu *vcpu)
+{
+ return -EOPNOTSUPP;
+}
+
+__weak int kvm_arch_vcpu_map_memory(struct kvm_vcpu *vcpu,
+ struct kvm_memory_mapping *mapping)
+{
+ return -EOPNOTSUPP;
+}
+
+static int kvm_vcpu_map_memory(struct kvm_vcpu *vcpu,
+ struct kvm_memory_mapping *mapping)
+{
+ bool added = false;
+ int idx, r = 0;
+
+ if (mapping->flags & ~(KVM_MEMORY_MAPPING_FLAG_WRITE |
+ KVM_MEMORY_MAPPING_FLAG_EXEC |
+ KVM_MEMORY_MAPPING_FLAG_USER |
+ KVM_MEMORY_MAPPING_FLAG_PRIVATE))
+ return -EINVAL;
+ if ((mapping->flags & KVM_MEMORY_MAPPING_FLAG_PRIVATE) &&
+ !kvm_arch_has_private_mem(vcpu->kvm))
+ return -EINVAL;
+
+ /* Sanity check */
+ if (!IS_ALIGNED(mapping->source, PAGE_SIZE) ||
+ !mapping->nr_pages ||
+ mapping->base_gfn + mapping->nr_pages <= mapping->base_gfn)
+ return -EINVAL;
+
+ vcpu_load(vcpu);
+ idx = srcu_read_lock(&vcpu->kvm->srcu);
+ r = kvm_arch_vcpu_pre_map_memory(vcpu);
+ if (r)
+ return r;
+
+ while (mapping->nr_pages) {
+ if (signal_pending(current)) {
+ r = -ERESTARTSYS;
+ break;
+ }
+
+ if (need_resched())
+ cond_resched();
+
+ r = kvm_arch_vcpu_map_memory(vcpu, mapping);
+ if (r)
+ break;
+
+ added = true;
+ }
+
+ srcu_read_unlock(&vcpu->kvm->srcu, idx);
+ vcpu_put(vcpu);
+
+ if (added && mapping->nr_pages > 0)
+ r = -EAGAIN;
+
+ return r;
+}
+
static long kvm_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
@@ -4620,6 +4683,17 @@ static long kvm_vcpu_ioctl(struct file *filp,
r = kvm_vcpu_ioctl_get_stats_fd(vcpu);
break;
}
+ case KVM_MAP_MEMORY: {
+ struct kvm_memory_mapping mapping;
+
+ r = -EFAULT;
+ if (copy_from_user(&mapping, argp, sizeof(mapping)))
+ break;
+ r = kvm_vcpu_map_memory(vcpu, &mapping);
+ if (copy_to_user(argp, &mapping, sizeof(mapping)))
+ r = -EFAULT;
+ break;
+ }
default:
r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
}
--
2.25.1
next prev parent reply other threads:[~2024-03-01 17:29 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-01 17:28 [RFC PATCH 0/8] KVM: Prepopulate guest memory API isaku.yamahata
2024-03-01 17:28 ` [RFC PATCH 1/8] KVM: Document KVM_MAP_MEMORY ioctl isaku.yamahata
2024-03-07 0:43 ` David Matlack
2024-03-07 1:29 ` Isaku Yamahata
2024-03-07 12:30 ` Huang, Kai
2024-03-07 20:33 ` Isaku Yamahata
2024-03-08 0:20 ` Huang, Kai
2024-03-08 0:56 ` David Matlack
2024-03-08 1:28 ` Sean Christopherson
2024-03-08 2:19 ` Isaku Yamahata
2024-03-10 23:12 ` Michael Roth
2024-03-11 1:05 ` Huang, Kai
2024-03-11 1:08 ` Huang, Kai
2024-03-12 1:34 ` Isaku Yamahata
2024-03-01 17:28 ` isaku.yamahata [this message]
2024-03-07 0:49 ` [RFC PATCH 2/8] KVM: Add KVM_MAP_MEMORY vcpu ioctl to pre-populate guest memory David Matlack
2024-03-07 2:52 ` Isaku Yamahata
2024-03-07 12:45 ` Huang, Kai
2024-03-07 20:41 ` Isaku Yamahata
2024-03-11 17:23 ` Sean Christopherson
2024-03-11 22:19 ` Isaku Yamahata
2024-03-01 17:28 ` [RFC PATCH 3/8] KVM: x86/mmu: Introduce initialier macro for struct kvm_page_fault isaku.yamahata
2024-03-11 17:24 ` Sean Christopherson
2024-03-11 22:56 ` Isaku Yamahata
2024-03-01 17:28 ` [RFC PATCH 4/8] KVM: x86/mmu: Factor out kvm_mmu_do_page_fault() isaku.yamahata
2024-03-01 17:28 ` [RFC PATCH 5/8] KVM: x86/mmu: Introduce kvm_mmu_map_page() for prepopulating guest memory isaku.yamahata
2024-03-07 0:38 ` David Matlack
2024-03-19 15:53 ` Isaku Yamahata
2024-03-11 17:29 ` Sean Christopherson
2024-03-11 22:57 ` Isaku Yamahata
2024-03-01 17:28 ` [RFC PATCH 6/8] KVM: x86: Implement kvm_arch_{, pre_}vcpu_map_memory() isaku.yamahata
2024-03-07 0:30 ` David Matlack
2024-03-07 0:36 ` David Matlack
2024-03-07 1:51 ` Isaku Yamahata
2024-03-19 16:26 ` Isaku Yamahata
2024-04-03 23:15 ` Sean Christopherson
2024-03-07 1:34 ` Isaku Yamahata
2024-03-11 23:26 ` Sean Christopherson
2024-03-12 12:38 ` Huang, Kai
2024-03-12 14:20 ` Sean Christopherson
2024-03-12 21:41 ` Huang, Kai
2024-03-12 21:46 ` Huang, Kai
2024-03-12 23:03 ` Sean Christopherson
2024-03-01 17:28 ` [RFC PATCH 7/8] KVM: x86: Add hooks in kvm_arch_vcpu_map_memory() isaku.yamahata
2024-03-01 17:28 ` [RFC PATCH 8/8] KVM: selftests: x86: Add test for KVM_MAP_MEMORY isaku.yamahata
2024-03-07 0:53 ` [RFC PATCH 0/8] KVM: Prepopulate guest memory API David Matlack
2024-03-07 2:09 ` Isaku Yamahata
2024-03-19 16:33 ` Isaku Yamahata
2024-04-03 18:30 ` Sean Christopherson
2024-04-03 22:00 ` Isaku Yamahata
2024-04-03 22:42 ` Sean Christopherson
2024-03-11 3:20 ` Michael Roth
2024-03-11 23:44 ` Sean Christopherson
2024-03-12 1:32 ` Isaku Yamahata
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