From d85dc283fa87353be10b11b463196d10eb49ca41 Mon Sep 17 00:00:00 2001 From: aliguori Date: Tue, 9 Dec 2008 19:59:09 +0000 Subject: [PATCH] Disable KVM support if the kernel modules have broken memory slot handling Prior to kvm-80, memory slot deletion was broken in the KVM kernel modules. In kvm-81, a new capability is introduced to signify that this problem has been fixed. Since we rely on being able to delete memory slots, refuse to work with any kernel module that does not have this capability present. Signed-off-by: Anthony Liguori git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5960 c046a42c-6fe2-441c-8c8c-71466251a162 --- configure | 3 ++- kvm-all.c | 15 +++++++++++++++ 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/configure b/configure index b90c47f..13f6358 100755 --- a/configure +++ b/configure @@ -933,7 +933,8 @@ if test "$kvm" = "yes" ; then KVM_API_VERSION < 12 || \ KVM_API_VERSION > 12 || \ !defined(KVM_CAP_USER_MEMORY) || \ - !defined(KVM_CAP_SET_TSS_ADDR) + !defined(KVM_CAP_SET_TSS_ADDR) || \ + !defined(KVM_CAP_DESTROY_MEMORY_REGION_WORKS) #error Invalid KVM version #endif int main(void) { return 0; } diff --git a/kvm-all.c b/kvm-all.c index 69ca46b..8615bf6 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -283,6 +283,21 @@ int kvm_init(int smp_cpus) goto err; } + /* There was a nasty bug in < kvm-80 that prevents memory slots from being + * destroyed properly. Since we rely on this capability, refuse to work + * with any kernel without this capability. */ + ret = kvm_ioctl(s, KVM_CHECK_EXTENSION, + KVM_CAP_DESTROY_MEMORY_REGION_WORKS); + if (ret <= 0) { + if (ret == 0) + ret = -EINVAL; + + fprintf(stderr, + "KVM kernel module broken (DESTROY_MEMORY_REGION)\n" + "Please upgrade to at least kvm-81.\n"); + goto err; + } + ret = kvm_arch_init(s, smp_cpus); if (ret < 0) goto err; -- 1.7.9.5