The patch titled
KVM: Expose MSRs to userspace (v2)
has been added to the -mm tree. Its filename is
kvm-expose-msrs-to-userspace-v2.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: KVM: Expose MSRs to userspace (v2)
From: Avi Kivity <avi@xxxxxxxxxxxx>
Changes from v1:
- get msrs and set msrs are now symmetric: both accept a list of msrs. it
is now possible to retrieve a single msr.
- a new KVM_GET_MSR_INDEX_LIST allows discovering which msrs are supported
by kvm (previously this was integrated into KVM_GET_MSRS)
- error handling is simpler and correcter
- the implementation is collapsed into a single msr_io() function
- avoid pointers in ioctl structs, instead use zero length arrays
Signed-off-by: Uri Lublin <uril@xxxxxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/kvm/kvm_main.c | 177 +++++++++++++++++----------------------
include/linux/kvm.h | 14 +--
2 files changed, 89 insertions(+), 102 deletions(-)
diff -puN drivers/kvm/kvm_main.c~kvm-expose-msrs-to-userspace-v2 drivers/kvm/kvm_main.c
--- a/drivers/kvm/kvm_main.c~kvm-expose-msrs-to-userspace-v2
+++ a/drivers/kvm/kvm_main.c
@@ -126,6 +126,8 @@ static const u32 vmx_msr_index[] = {
#define MSR_IA32_VMX_EXIT_CTLS_MSR 0x483
#define MSR_IA32_VMX_ENTRY_CTLS_MSR 0x484
+#define MAX_IO_MSRS 256
+
#define CR0_RESEVED_BITS 0xffffffff1ffaffc0ULL
#define LMSW_GUEST_MASK 0x0eULL
#define CR4_RESEVED_BITS (~((1ULL << 11) - 1))
@@ -3147,7 +3149,7 @@ static int kvm_dev_ioctl_set_sregs(struc
/*
* List of msr numbers which we expose to userspace through KVM_GET_MSRS
- * and KVM_SET_MSRS.
+ * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
*/
static u32 msrs_to_save[] = {
MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
@@ -3158,110 +3160,91 @@ static u32 msrs_to_save[] = {
MSR_IA32_TIME_STAMP_COUNTER,
};
-static int kvm_dev_ioctl_get_msrs(struct kvm *kvm, struct kvm_msrs *msrs)
+
+/*
+ * Adapt set_msr() to msr_io()'s calling convention
+ */
+static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
+{
+ return set_msr(vcpu, index, *data);
+}
+
+/*
+ * Read or write a bunch of msrs. All parameters are kernel addresses.
+ *
+ * @return number of msrs set successfully.
+ */
+static int __msr_io(struct kvm *kvm, struct kvm_msrs *msrs,
+ struct kvm_msr_entry *entries,
+ int (*do_msr)(struct kvm_vcpu *vcpu,
+ unsigned index, u64 *data))
{
struct kvm_vcpu *vcpu;
- struct kvm_msr_entry *entry, *entries;
- int rc;
- u32 size, num_entries, i;
+ int i;
if (msrs->vcpu < 0 || msrs->vcpu >= KVM_MAX_VCPUS)
return -EINVAL;
- num_entries = ARRAY_SIZE(msrs_to_save);
- if (msrs->nmsrs < num_entries) {
- /* inform actual number of entries */
- msrs->nmsrs = num_entries;
- return -EINVAL;
- }
-
vcpu = vcpu_load(kvm, msrs->vcpu);
if (!vcpu)
return -ENOENT;
- msrs->nmsrs = num_entries; /* update to actual number of entries */
- size = msrs->nmsrs * sizeof(struct kvm_msr_entry);
- rc = -E2BIG;
- if (size > 4096)
- goto out_vcpu;
-
- rc = -ENOMEM;
- entries = vmalloc(size);
- if (entries == NULL)
- goto out_vcpu;
-
- memset(entries, 0, size);
- rc = -EINVAL;
- for (i=0; i<num_entries; i++) {
- entry = &entries[i];
- entry->index = msrs_to_save[i];
- if (get_msr(vcpu, entry->index, &entry->data))
- goto out_free;
- }
-
- rc = -EFAULT;
- if (copy_to_user(msrs->entries, entries, size))
- goto out_free;
-
- rc = 0;
-out_free:
- vfree(entries);
+ for (i = 0; i < msrs->nmsrs; ++i)
+ if (do_msr(vcpu, entries[i].index, &entries[i].data))
+ break;
-out_vcpu:
vcpu_put(vcpu);
- return rc;
+ return i;
}
-static int kvm_dev_ioctl_set_msrs(struct kvm *kvm, struct kvm_msrs *msrs)
-{
- struct kvm_vcpu *vcpu;
- struct kvm_msr_entry *entry, *entries;
- int rc;
- u32 size, num_entries, i;
+/*
+ * Read or write a bunch of msrs. Parameters are user addresses.
+ *
+ * @return number of msrs set successfully.
+ */
+static int msr_io(struct kvm *kvm, struct kvm_msrs __user *user_msrs,
+ int (*do_msr)(struct kvm_vcpu *vcpu,
+ unsigned index, u64 *data),
+ int writeback)
+{
+ struct kvm_msrs msrs;
+ struct kvm_msr_entry *entries;
+ int r, n;
+ unsigned size;
- if (msrs->vcpu < 0 || msrs->vcpu >= KVM_MAX_VCPUS)
- return -EINVAL;
+ r = -EFAULT;
+ if (copy_from_user(&msrs, user_msrs, sizeof msrs))
+ goto out;
- num_entries = ARRAY_SIZE(msrs_to_save);
- if (msrs->nmsrs < num_entries) {
- msrs->nmsrs = num_entries; /* inform actual size */
- return -EINVAL;
- }
+ r = -E2BIG;
+ if (msrs.nmsrs >= MAX_IO_MSRS)
+ goto out;
- vcpu = vcpu_load(kvm, msrs->vcpu);
- if (!vcpu)
- return -ENOENT;
+ r = -ENOMEM;
+ size = sizeof(struct kvm_msr_entry) * msrs.nmsrs;
+ entries = vmalloc(size);
+ if (!entries)
+ goto out;
- size = msrs->nmsrs * sizeof(struct kvm_msr_entry);
- rc = -E2BIG;
- if (size > 4096)
- goto out_vcpu;
+ r = -EFAULT;
+ if (copy_from_user(entries, user_msrs->entries, size))
+ goto out_free;
- rc = -ENOMEM;
- entries = vmalloc(size);
- if (entries == NULL)
- goto out_vcpu;
+ r = n = __msr_io(kvm, &msrs, entries, do_msr);
+ if (r < 0)
+ goto out_free;
- rc = -EFAULT;
- if (copy_from_user(entries, msrs->entries, size))
+ r = -EFAULT;
+ if (writeback && copy_to_user(user_msrs->entries, entries, size))
goto out_free;
- rc = -EINVAL;
- for (i=0; i<num_entries; i++) {
- entry = &entries[i];
- if (set_msr(vcpu, entry->index, entry->data))
- goto out_free;
- }
+ r = n;
- rc = 0;
out_free:
vfree(entries);
-
-out_vcpu:
- vcpu_put(vcpu);
-
- return rc;
+out:
+ return r;
}
/*
@@ -3505,32 +3488,32 @@ static long kvm_dev_ioctl(struct file *f
goto out;
break;
}
- case KVM_GET_MSRS: {
- struct kvm_msrs kvm_msrs;
+ case KVM_GET_MSRS:
+ r = msr_io(kvm, (void __user *)arg, get_msr, 1);
+ break;
+ case KVM_SET_MSRS:
+ r = msr_io(kvm, (void __user *)arg, do_set_msr, 0);
+ break;
+ case KVM_GET_MSR_INDEX_LIST: {
+ struct kvm_msr_list __user *user_msr_list = (void __user *)arg;
+ struct kvm_msr_list msr_list;
+ unsigned n;
r = -EFAULT;
- if (copy_from_user(&kvm_msrs, (void *)arg, sizeof kvm_msrs))
+ if (copy_from_user(&msr_list, user_msr_list, sizeof msr_list))
goto out;
- r = kvm_dev_ioctl_get_msrs(kvm, &kvm_msrs);
- if (r)
+ n = msr_list.nmsrs;
+ msr_list.nmsrs = ARRAY_SIZE(msrs_to_save);
+ if (copy_to_user(user_msr_list, &msr_list, sizeof msr_list))
goto out;
- r = -EFAULT;
- if (copy_to_user((void *)arg, &kvm_msrs, sizeof kvm_msrs))
+ r = -E2BIG;
+ if (n < ARRAY_SIZE(msrs_to_save))
goto out;
- r = 0;
- break;
- }
- case KVM_SET_MSRS: {
- struct kvm_msrs kvm_msrs;
-
r = -EFAULT;
- if (copy_from_user(&kvm_msrs, (void *)arg, sizeof kvm_msrs))
- goto out;
- r = kvm_dev_ioctl_set_msrs(kvm, &kvm_msrs);
- if (r)
+ if (copy_to_user(user_msr_list->indices, &msrs_to_save,
+ sizeof msrs_to_save))
goto out;
r = 0;
- break;
}
default:
;
diff -puN include/linux/kvm.h~kvm-expose-msrs-to-userspace-v2 include/linux/kvm.h
--- a/include/linux/kvm.h~kvm-expose-msrs-to-userspace-v2
+++ a/include/linux/kvm.h
@@ -152,10 +152,13 @@ struct kvm_msrs {
__u32 vcpu;
__u32 nmsrs; /* number of msrs in entries */
- union {
- struct kvm_msr_entry __user *entries;
- __u64 padding;
- };
+ struct kvm_msr_entry entries[0];
+};
+
+/* for KVM_GET_MSR_INDEX_LIST */
+struct kvm_msr_list {
+ __u32 nmsrs; /* number of msrs in entries */
+ __u32 indices[0];
};
/* for KVM_TRANSLATE */
@@ -218,6 +221,7 @@ struct kvm_dirty_log {
#define KVM_CREATE_VCPU _IOW(KVMIO, 11, int /* vcpu_slot */)
#define KVM_GET_DIRTY_LOG _IOW(KVMIO, 12, struct kvm_dirty_log)
#define KVM_GET_MSRS _IOWR(KVMIO, 13, struct kvm_msrs)
-#define KVM_SET_MSRS _IOW(KVMIO, 14, struct kvm_msrs)
+#define KVM_SET_MSRS _IOWR(KVMIO, 14, struct kvm_msrs)
+#define KVM_GET_MSR_INDEX_LIST _IOWR(KVMIO, 15, struct kvm_msr_list)
#endif
_
Patches currently in -mm which might be from avi@xxxxxxxxxxxx are
kvm-userspace-interface.patch
kvm-intel-virtual-mode-extensions-definitions.patch
kvm-kvm-data-structures.patch
kvm-random-accessors-and-constants.patch
kvm-virtualization-infrastructure.patch
kvm-virtualization-infrastructure-kvm-fix-guest-cr4-corruption.patch
kvm-virtualization-infrastructure-include-desch.patch
kvm-virtualization-infrastructure-fix-segment-state-changes-across-processor-mode-switches.patch
kvm-virtualization-infrastructure-fix-asm-constraints-for-segment-loads.patch
kvm-virtualization-infrastructure-fix-mmu-reset-locking-when-setting-cr0.patch
kvm-memory-slot-management.patch
kvm-vcpu-creation-and-maintenance.patch
kvm-vcpu-creation-and-maintenance-segment-access-cleanup.patch
kvm-workaround-cr0cd-cache-disable-bit-leak-from-guest-to.patch
kvm-vcpu-execution-loop.patch
kvm-define-exit-handlers.patch
kvm-define-exit-handlers-pass-fs-gs-segment-bases-to-x86-emulator.patch
kvm-less-common-exit-handlers.patch
kvm-less-common-exit-handlers-handle-rdmsrmsr_efer.patch
kvm-mmu.patch
kvm-x86-emulator.patch
kvm-x86-emulator-fix-emulator-mov-cr-decoding.patch
kvm-plumbing.patch
kvm-dynamically-determine-which-msrs-to-load-and-save.patch
kvm-fix-calculation-of-initial-value-of-rdx-register.patch
kvm-avoid-using-vmx-instruction-directly.patch
kvm-avoid-using-vmx-instruction-directly-fix-asm-constraints.patch
kvm-expose-interrupt-bitmap.patch
kvm-add-time-stamp-counter-msr-and-accessors.patch
kvm-expose-msrs-to-userspace.patch
kvm-expose-msrs-to-userspace-v2.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
