[PATCH 1/3] target-i386: kvm: Abort if MCE bank count is not supported by host

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Instead of silently changing the number of banks in mcg_cap based
on kvm_get_mce_cap_supported(), abort initialization if the host
doesn't support MCE_BANKS_DEF banks.

Note that MCE_BANKS_DEF was always 10 since it was introduced in
QEMU, and Linux always returned 32 at KVM_CAP_MCE since
KVM_CAP_MCE was introduced, so no behavior is being changed and
the error can't be triggered by any Linux version. The point of
the new check is to ensure we won't silently change the bank
count if we change MCE_BANKS_DEF or make the bank count
configurable in the future.

Signed-off-by: Eduardo Habkost <ehabkost@xxxxxxxxxx>
---
 target-i386/kvm.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 2a9953b..ee7bc69 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -784,11 +784,14 @@ int kvm_arch_init_vcpu(CPUState *cs)
             return ret;
         }
 
-        if (banks > MCE_BANKS_DEF) {
-            banks = MCE_BANKS_DEF;
+        if (MCE_BANKS_DEF > banks) {
+            error_report("kvm: Unsupported MCE bank count: %d > %d\n",
+                         MCE_BANKS_DEF, banks);
+            return -ENOTSUP;
         }
+
         mcg_cap &= MCE_CAP_DEF;
-        mcg_cap |= banks;
+        mcg_cap |= MCE_BANKS_DEF;
         ret = kvm_vcpu_ioctl(cs, KVM_X86_SETUP_MCE, &mcg_cap);
         if (ret < 0) {
             fprintf(stderr, "KVM_X86_SETUP_MCE: %s", strerror(-ret));
-- 
2.1.0

--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux