From 4cd481f68dde99ac416003b825c835f71e364393 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Mon, 13 Apr 2009 11:59:32 +0200 Subject: [PATCH] KVM: Fix overlapping check for memory slots When checking for overlapping slots on registration of a new one, kvm currently also considers zero-length (ie. deleted) slots and rejects requests incorrectly. This finally denies user space from joining slots. Fix the check by skipping deleted slots and advertise this via a KVM_CAP_JOIN_MEMORY_REGIONS_WORKS. Cc: stable@kernel.org Signed-off-by: Jan Kiszka Signed-off-by: Avi Kivity --- include/linux/kvm.h | 2 ++ virt/kvm/kvm_main.c | 3 ++- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/include/linux/kvm.h b/include/linux/kvm.h index 311a073afe8a..8cc137911b34 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -409,6 +409,8 @@ struct kvm_trace_rec { #ifdef __KVM_HAVE_DEVICE_ASSIGNMENT #define KVM_CAP_DEVICE_DEASSIGNMENT 27 #endif +/* Another bug in KVM_SET_USER_MEMORY_REGION fixed: */ +#define KVM_CAP_JOIN_MEMORY_REGIONS_WORKS 30 #ifdef KVM_CAP_IRQ_ROUTING diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 28d693a1ee8f..1ecbe2391c8b 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -961,7 +961,7 @@ int __kvm_set_memory_region(struct kvm *kvm, for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { struct kvm_memory_slot *s = &kvm->memslots[i]; - if (s == memslot) + if (s == memslot || !s->npages) continue; if (!((base_gfn + npages <= s->base_gfn) || (base_gfn >= s->base_gfn + s->npages))) @@ -1983,6 +1983,7 @@ static long kvm_dev_ioctl_check_extension_generic(long arg) switch (arg) { case KVM_CAP_USER_MEMORY: case KVM_CAP_DESTROY_MEMORY_REGION_WORKS: + case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS: return 1; #ifdef CONFIG_HAVE_KVM_IRQCHIP case KVM_CAP_IRQ_ROUTING: -- 2.39.2