From 86044c8c14b618b11558d3cba96aa0548c81274d Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Thu, 26 Feb 2015 13:53:47 +0100 Subject: [PATCH] KVM: s390/cpacf: Fix kernel bug under z/VM Under z/VM PQAP might trigger an operation exception if no crypto cards are defined via APVIRTUAL or APDEDICATED. [ 386.098666] Kernel BUG at 0000000000135c56 [verbose debug info unavailable] [ 386.098693] illegal operation: 0001 ilc:2 [#1] SMP [...] [ 386.098751] Krnl PSW : 0704c00180000000 0000000000135c56 (kvm_s390_apxa_installed+0x46/0x98) [...] [ 386.098804] [<000000000013627c>] kvm_arch_init_vm+0x29c/0x358 [ 386.098806] [<000000000012d008>] kvm_dev_ioctl+0xc0/0x460 [ 386.098809] [<00000000002c639a>] do_vfs_ioctl+0x332/0x508 [ 386.098811] [<00000000002c660e>] SyS_ioctl+0x9e/0xb0 [ 386.098814] [<000000000070476a>] system_call+0xd6/0x258 [ 386.098815] [<000003fffc7400a2>] 0x3fffc7400a2 Lets add an extable entry and provide a zeroed config in that case. Reported-by: Stefan Zimmermann Signed-off-by: Christian Borntraeger Reviewed-by: Thomas Huth Tested-by: Stefan Zimmermann --- arch/s390/kvm/kvm-s390.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index b4d2030c22eb..18965f91d39e 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -778,15 +778,18 @@ long kvm_arch_vm_ioctl(struct file *filp, static int kvm_s390_query_ap_config(u8 *config) { u32 fcn_code = 0x04000000UL; - u32 cc; + u32 cc = 0; + memset(config, 0, 128); asm volatile( "lgr 0,%1\n" "lgr 2,%2\n" ".long 0xb2af0000\n" /* PQAP(QCI) */ - "ipm %0\n" + "0: ipm %0\n" "srl %0,28\n" - : "=r" (cc) + "1:\n" + EX_TABLE(0b, 1b) + : "+r" (cc) : "r" (fcn_code), "r" (config) : "cc", "0", "2", "memory" );