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authorThomas Huth <thuth@redhat.com>2023-02-08 15:01:02 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2023-03-16 10:18:06 -0400
commitc5edd753a0bd6243a597f5199c227a50457ee179 (patch)
tree97ac32a01375357a35638ee6e6d701cb430be073
parent71fb165e23e3b66e68ca7baab6c317c2663c32d5 (diff)
downloadlwn-c5edd753a0bd6243a597f5199c227a50457ee179.tar.gz
lwn-c5edd753a0bd6243a597f5199c227a50457ee179.zip
KVM: x86: Remove the KVM_GET_NR_MMU_PAGES ioctl
The KVM_GET_NR_MMU_PAGES ioctl is quite questionable on 64-bit hosts since it fails to return the full 64 bits of the value that can be set with the corresponding KVM_SET_NR_MMU_PAGES call. Its "long" return value is truncated into an "int" in the kvm_arch_vm_ioctl() function. Since this ioctl also never has been used by userspace applications (QEMU, Google's internal VMM, kvmtool and CrosVM have been checked), it's likely the best if we remove this badly designed ioctl before anybody really tries to use it. Signed-off-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20230208140105.655814-4-thuth@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/x86.c8
-rw-r--r--include/uapi/linux/kvm.h2
-rw-r--r--tools/include/uapi/linux/kvm.h2
3 files changed, 2 insertions, 10 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ff7f398a0c6a..4282daeaee84 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6021,11 +6021,6 @@ static int kvm_vm_ioctl_set_nr_mmu_pages(struct kvm *kvm,
return 0;
}
-static unsigned long kvm_vm_ioctl_get_nr_mmu_pages(struct kvm *kvm)
-{
- return kvm->arch.n_max_mmu_pages;
-}
-
static int kvm_vm_ioctl_get_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
{
struct kvm_pic *pic = kvm->arch.vpic;
@@ -6711,9 +6706,6 @@ set_identity_unlock:
case KVM_SET_NR_MMU_PAGES:
r = kvm_vm_ioctl_set_nr_mmu_pages(kvm, arg);
break;
- case KVM_GET_NR_MMU_PAGES:
- r = kvm_vm_ioctl_get_nr_mmu_pages(kvm);
- break;
case KVM_CREATE_IRQCHIP: {
mutex_lock(&kvm->lock);
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index d77aef872a0a..4003a166328c 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1451,7 +1451,7 @@ struct kvm_vfio_spapr_tce {
#define KVM_CREATE_VCPU _IO(KVMIO, 0x41)
#define KVM_GET_DIRTY_LOG _IOW(KVMIO, 0x42, struct kvm_dirty_log)
#define KVM_SET_NR_MMU_PAGES _IO(KVMIO, 0x44)
-#define KVM_GET_NR_MMU_PAGES _IO(KVMIO, 0x45)
+#define KVM_GET_NR_MMU_PAGES _IO(KVMIO, 0x45) /* deprecated */
#define KVM_SET_USER_MEMORY_REGION _IOW(KVMIO, 0x46, \
struct kvm_userspace_memory_region)
#define KVM_SET_TSS_ADDR _IO(KVMIO, 0x47)
diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h
index d77aef872a0a..4003a166328c 100644
--- a/tools/include/uapi/linux/kvm.h
+++ b/tools/include/uapi/linux/kvm.h
@@ -1451,7 +1451,7 @@ struct kvm_vfio_spapr_tce {
#define KVM_CREATE_VCPU _IO(KVMIO, 0x41)
#define KVM_GET_DIRTY_LOG _IOW(KVMIO, 0x42, struct kvm_dirty_log)
#define KVM_SET_NR_MMU_PAGES _IO(KVMIO, 0x44)
-#define KVM_GET_NR_MMU_PAGES _IO(KVMIO, 0x45)
+#define KVM_GET_NR_MMU_PAGES _IO(KVMIO, 0x45) /* deprecated */
#define KVM_SET_USER_MEMORY_REGION _IOW(KVMIO, 0x46, \
struct kvm_userspace_memory_region)
#define KVM_SET_TSS_ADDR _IO(KVMIO, 0x47)