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-rw-r--r--Documentation/virt/kvm/api.rst19
-rw-r--r--Documentation/virt/kvm/cpuid.rst7
-rw-r--r--Documentation/virt/kvm/hypercalls.rst21
-rw-r--r--Documentation/virt/kvm/msr.rst13
-rw-r--r--arch/x86/include/asm/kvm_host.h2
-rw-r--r--arch/x86/include/uapi/asm/kvm_para.h13
-rw-r--r--arch/x86/kvm/x86.c46
-rw-r--r--include/uapi/linux/kvm.h1
-rw-r--r--include/uapi/linux/kvm_para.h1
9 files changed, 123 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index cded99561adf..e328caa35d6c 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -6950,3 +6950,22 @@ guest according to the bits Hyper-V CPUID feature leaves. Otherwise, all
currently implmented Hyper-V features are provided unconditionally when
Hyper-V identification is set in the HYPERV_CPUID_INTERFACE (0x40000001)
leaf.
+
+8.34 KVM_CAP_EXIT_HYPERCALL
+---------------------------
+
+:Capability: KVM_CAP_EXIT_HYPERCALL
+:Architectures: x86
+:Type: vm
+
+This capability, if enabled, will cause KVM to exit to userspace
+with KVM_EXIT_HYPERCALL exit reason to process some hypercalls.
+
+Calling KVM_CHECK_EXTENSION for this capability will return a bitmask
+of hypercalls that can be configured to exit to userspace.
+Right now, the only such hypercall is KVM_HC_MAP_GPA_RANGE.
+
+The argument to KVM_ENABLE_CAP is also a bitmask, and must be a subset
+of the result of KVM_CHECK_EXTENSION. KVM will forward to userspace
+the hypercalls whose corresponding bit is in the argument, and return
+ENOSYS for the others.
diff --git a/Documentation/virt/kvm/cpuid.rst b/Documentation/virt/kvm/cpuid.rst
index cf62162d4be2..bda3e3e737d7 100644
--- a/Documentation/virt/kvm/cpuid.rst
+++ b/Documentation/virt/kvm/cpuid.rst
@@ -96,6 +96,13 @@ KVM_FEATURE_MSI_EXT_DEST_ID 15 guest checks this feature bit
before using extended destination
ID bits in MSI address bits 11-5.
+KVM_FEATURE_HC_MAP_GPA_RANGE 16 guest checks this feature bit before
+ using the map gpa range hypercall
+ to notify the page state change
+
+KVM_FEATURE_MIGRATION_CONTROL 17 guest checks this feature bit before
+ using MSR_KVM_MIGRATION_CONTROL
+
KVM_FEATURE_CLOCKSOURCE_STABLE_BIT 24 host will warn if no guest-side
per-cpu warps are expected in
kvmclock
diff --git a/Documentation/virt/kvm/hypercalls.rst b/Documentation/virt/kvm/hypercalls.rst
index ed4fddd364ea..e56fa8b9cfca 100644
--- a/Documentation/virt/kvm/hypercalls.rst
+++ b/Documentation/virt/kvm/hypercalls.rst
@@ -169,3 +169,24 @@ a0: destination APIC ID
:Usage example: When sending a call-function IPI-many to vCPUs, yield if
any of the IPI target vCPUs was preempted.
+
+8. KVM_HC_MAP_GPA_RANGE
+-------------------------
+:Architecture: x86
+:Status: active
+:Purpose: Request KVM to map a GPA range with the specified attributes.
+
+a0: the guest physical address of the start page
+a1: the number of (4kb) pages (must be contiguous in GPA space)
+a2: attributes
+
+ Where 'attributes' :
+ * bits 3:0 - preferred page size encoding 0 = 4kb, 1 = 2mb, 2 = 1gb, etc...
+ * bit 4 - plaintext = 0, encrypted = 1
+ * bits 63:5 - reserved (must be zero)
+
+**Implementation note**: this hypercall is implemented in userspace via
+the KVM_CAP_EXIT_HYPERCALL capability. Userspace must enable that capability
+before advertising KVM_FEATURE_HC_MAP_GPA_RANGE in the guest CPUID. In
+addition, if the guest supports KVM_FEATURE_MIGRATION_CONTROL, userspace
+must also set up an MSR filter to process writes to MSR_KVM_MIGRATION_CONTROL.
diff --git a/Documentation/virt/kvm/msr.rst b/Documentation/virt/kvm/msr.rst
index e37a14c323d2..9315fc385fb0 100644
--- a/Documentation/virt/kvm/msr.rst
+++ b/Documentation/virt/kvm/msr.rst
@@ -376,3 +376,16 @@ data:
write '1' to bit 0 of the MSR, this causes the host to re-scan its queue
and check if there are more notifications pending. The MSR is available
if KVM_FEATURE_ASYNC_PF_INT is present in CPUID.
+
+MSR_KVM_MIGRATION_CONTROL:
+ 0x4b564d08
+
+data:
+ This MSR is available if KVM_FEATURE_MIGRATION_CONTROL is present in
+ CPUID. Bit 0 represents whether live migration of the guest is allowed.
+
+ When a guest is started, bit 0 will be 0 if the guest has encrypted
+ memory and 1 if the guest does not have encrypted memory. If the
+ guest is communicating page encryption status to the host using the
+ ``KVM_HC_MAP_GPA_RANGE`` hypercall, it can set bit 0 in this MSR to
+ allow live migration of the guest.
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index a0c29e29dd48..e11d64aa0bcd 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1087,6 +1087,8 @@ struct kvm_arch {
u32 user_space_msr_mask;
struct kvm_x86_msr_filter __rcu *msr_filter;
+ u32 hypercall_exit_enabled;
+
/* Guest can access the SGX PROVISIONKEY. */
bool sgx_provisioning_allowed;
diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
index 950afebfba88..5146bbab84d4 100644
--- a/arch/x86/include/uapi/asm/kvm_para.h
+++ b/arch/x86/include/uapi/asm/kvm_para.h
@@ -33,6 +33,8 @@
#define KVM_FEATURE_PV_SCHED_YIELD 13
#define KVM_FEATURE_ASYNC_PF_INT 14
#define KVM_FEATURE_MSI_EXT_DEST_ID 15
+#define KVM_FEATURE_HC_MAP_GPA_RANGE 16
+#define KVM_FEATURE_MIGRATION_CONTROL 17
#define KVM_HINTS_REALTIME 0
@@ -54,6 +56,7 @@
#define MSR_KVM_POLL_CONTROL 0x4b564d05
#define MSR_KVM_ASYNC_PF_INT 0x4b564d06
#define MSR_KVM_ASYNC_PF_ACK 0x4b564d07
+#define MSR_KVM_MIGRATION_CONTROL 0x4b564d08
struct kvm_steal_time {
__u64 steal;
@@ -90,6 +93,16 @@ struct kvm_clock_pairing {
/* MSR_KVM_ASYNC_PF_INT */
#define KVM_ASYNC_PF_VEC_MASK GENMASK(7, 0)
+/* MSR_KVM_MIGRATION_CONTROL */
+#define KVM_MIGRATION_READY (1 << 0)
+
+/* KVM_HC_MAP_GPA_RANGE */
+#define KVM_MAP_GPA_RANGE_PAGE_SZ_4K 0
+#define KVM_MAP_GPA_RANGE_PAGE_SZ_2M (1 << 0)
+#define KVM_MAP_GPA_RANGE_PAGE_SZ_1G (1 << 1)
+#define KVM_MAP_GPA_RANGE_ENC_STAT(n) (n << 4)
+#define KVM_MAP_GPA_RANGE_ENCRYPTED KVM_MAP_GPA_RANGE_ENC_STAT(1)
+#define KVM_MAP_GPA_RANGE_DECRYPTED KVM_MAP_GPA_RANGE_ENC_STAT(0)
/* Operations for KVM_HC_MMU_OP */
#define KVM_MMU_OP_WRITE_PTE 1
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ceb60f64085c..8b898ec8d349 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -103,6 +103,8 @@ static u64 __read_mostly efer_reserved_bits = ~((u64)EFER_SCE);
static u64 __read_mostly cr4_reserved_bits = CR4_RESERVED_BITS;
+#define KVM_EXIT_HYPERCALL_VALID_MASK (1 << KVM_HC_MAP_GPA_RANGE)
+
#define KVM_X2APIC_API_VALID_FLAGS (KVM_X2APIC_API_USE_32BIT_IDS | \
KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK)
@@ -3996,6 +3998,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_SREGS2:
r = 1;
break;
+ case KVM_CAP_EXIT_HYPERCALL:
+ r = KVM_EXIT_HYPERCALL_VALID_MASK;
+ break;
case KVM_CAP_SET_GUEST_DEBUG2:
return KVM_GUESTDBG_VALID_MASK;
#ifdef CONFIG_KVM_XEN
@@ -5622,6 +5627,14 @@ split_irqchip_unlock:
if (kvm_x86_ops.vm_copy_enc_context_from)
r = kvm_x86_ops.vm_copy_enc_context_from(kvm, cap->args[0]);
return r;
+ case KVM_CAP_EXIT_HYPERCALL:
+ if (cap->args[0] & ~KVM_EXIT_HYPERCALL_VALID_MASK) {
+ r = -EINVAL;
+ break;
+ }
+ kvm->arch.hypercall_exit_enabled = cap->args[0];
+ r = 0;
+ break;
default:
r = -EINVAL;
break;
@@ -8548,6 +8561,17 @@ no_yield:
return;
}
+static int complete_hypercall_exit(struct kvm_vcpu *vcpu)
+{
+ u64 ret = vcpu->run->hypercall.ret;
+
+ if (!is_64_bit_mode(vcpu))
+ ret = (u32)ret;
+ kvm_rax_write(vcpu, ret);
+ ++vcpu->stat.hypercalls;
+ return kvm_skip_emulated_instruction(vcpu);
+}
+
int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
{
unsigned long nr, a0, a1, a2, a3, ret;
@@ -8613,6 +8637,28 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
kvm_sched_yield(vcpu, a0);
ret = 0;
break;
+ case KVM_HC_MAP_GPA_RANGE: {
+ u64 gpa = a0, npages = a1, attrs = a2;
+
+ ret = -KVM_ENOSYS;
+ if (!(vcpu->kvm->arch.hypercall_exit_enabled & (1 << KVM_HC_MAP_GPA_RANGE)))
+ break;
+
+ if (!PAGE_ALIGNED(gpa) || !npages ||
+ gpa_to_gfn(gpa) + npages <= gpa_to_gfn(gpa)) {
+ ret = -KVM_EINVAL;
+ break;
+ }
+
+ vcpu->run->exit_reason = KVM_EXIT_HYPERCALL;
+ vcpu->run->hypercall.nr = KVM_HC_MAP_GPA_RANGE;
+ vcpu->run->hypercall.args[0] = gpa;
+ vcpu->run->hypercall.args[1] = npages;
+ vcpu->run->hypercall.args[2] = attrs;
+ vcpu->run->hypercall.longmode = op_64_bit;
+ vcpu->arch.complete_userspace_io = complete_hypercall_exit;
+ return 0;
+ }
default:
ret = -KVM_ENOSYS;
break;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 90d44138dbfb..9febe1412f7a 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1085,6 +1085,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_PTP_KVM 198
#define KVM_CAP_HYPERV_ENFORCE_CPUID 199
#define KVM_CAP_SREGS2 200
+#define KVM_CAP_EXIT_HYPERCALL 201
#ifdef KVM_CAP_IRQ_ROUTING
diff --git a/include/uapi/linux/kvm_para.h b/include/uapi/linux/kvm_para.h
index 8b86609849b9..960c7e93d1a9 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_MAP_GPA_RANGE 12
/*
* hypercalls use architecture specific
generated by cgit v1.2.3 (git 2.39.0) at 2024-08-02 15:19:04 +0300