KVM: s390: Make psw available on all exits, not just a subset

This patch moves s390 processor status word into the base kvm_run
struct and keeps it up-to date on all userspace exits.

The userspace ABI is broken by this, however there are no applications
in the wild using this.  A capability check is provided so users can
verify the updated API exists.

Cc: stable@kernel.org
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/s390/include/asm/kvm.h b/arch/s390/include/asm/kvm.h
index 3dfcaeb5d7f4f14fa8705b2244495e4c3795ca3a..82b32a100c7ddc18f69547ca40ec946e873852c6 100644 (file)
--- a/arch/s390/include/asm/kvm.h
+++ b/arch/s390/include/asm/kvm.h
@@ -1,6 +1,5 @@
 #ifndef __LINUX_KVM_S390_H
 #define __LINUX_KVM_S390_H
-
 /*
  * asm-s390/kvm.h - KVM s390 specific structures and definitions
  *
@@ -15,6 +14,8 @@
  */
 #include <linux/types.h>
 
+#define __KVM_S390
+
 /* for KVM_GET_REGS and KVM_SET_REGS */
 struct kvm_regs {
        /* general purpose regs for s390 */

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 544505893c9fd8befb48b2f8943819ffb13d3ea6..f8bcaefd7d3458bec798afc96ccd76f4e2eb2d06 100644 (file)
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -117,10 +117,16 @@ long kvm_arch_dev_ioctl(struct file *filp,
 
 int kvm_dev_ioctl_check_extension(long ext)
 {
+       int r;
+
        switch (ext) {
+       case KVM_CAP_S390_PSW:
+               r = 1;
+               break;
        default:
-               return 0;
+               r = 0;
        }
+       return r;
 }
 
 /* Section: vm related */
@@ -420,8 +426,10 @@ static int kvm_arch_vcpu_ioctl_set_initial_psw(struct kvm_vcpu *vcpu, psw_t psw)
        vcpu_load(vcpu);
        if (atomic_read(&vcpu->arch.sie_block->cpuflags) & CPUSTAT_RUNNING)
                rc = -EBUSY;
-       else
-               vcpu->arch.sie_block->gpsw = psw;
+       else {
+               vcpu->run->psw_mask = psw.mask;
+               vcpu->run->psw_addr = psw.addr;
+       }
        vcpu_put(vcpu);
        return rc;
 }
@@ -509,9 +517,6 @@ rerun_vcpu:
 
        switch (kvm_run->exit_reason) {
        case KVM_EXIT_S390_SIEIC:
-               vcpu->arch.sie_block->gpsw.mask = kvm_run->s390_sieic.mask;
-               vcpu->arch.sie_block->gpsw.addr = kvm_run->s390_sieic.addr;
-               break;
        case KVM_EXIT_UNKNOWN:
        case KVM_EXIT_INTR:
        case KVM_EXIT_S390_RESET:
@@ -520,6 +525,9 @@ rerun_vcpu:
                BUG();
        }
 
+       vcpu->arch.sie_block->gpsw.mask = kvm_run->psw_mask;
+       vcpu->arch.sie_block->gpsw.addr = kvm_run->psw_addr;
+
        might_fault();
 
        do {
@@ -539,8 +547,6 @@ rerun_vcpu:
                /* intercept cannot be handled in-kernel, prepare kvm-run */
                kvm_run->exit_reason         = KVM_EXIT_S390_SIEIC;
                kvm_run->s390_sieic.icptcode = vcpu->arch.sie_block->icptcode;
-               kvm_run->s390_sieic.mask     = vcpu->arch.sie_block->gpsw.mask;
-               kvm_run->s390_sieic.addr     = vcpu->arch.sie_block->gpsw.addr;
                kvm_run->s390_sieic.ipa      = vcpu->arch.sie_block->ipa;
                kvm_run->s390_sieic.ipb      = vcpu->arch.sie_block->ipb;
                rc = 0;
@@ -552,6 +558,9 @@ rerun_vcpu:
                rc = 0;
        }
 
+       kvm_run->psw_mask     = vcpu->arch.sie_block->gpsw.mask;
+       kvm_run->psw_addr     = vcpu->arch.sie_block->gpsw.addr;
+
        if (vcpu->sigset_active)
                sigprocmask(SIG_SETMASK, &sigsaved, NULL);
 

diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 92045a92d714dacdfc150b4ac7dae1b996fcb85d..2d241da07236fd10b8e3ad5b8e8df415a95bb9ef 100644 (file)
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -181,6 +181,11 @@ struct kvm_run {
        __u64 cr8;
        __u64 apic_base;
 
+#ifdef __KVM_S390
+       /* the processor status word for s390 */
+       __u64 psw_mask; /* psw upper half */
+       __u64 psw_addr; /* psw lower half */
+#endif
        union {
                /* KVM_EXIT_UNKNOWN */
                struct {
@@ -232,8 +237,6 @@ struct kvm_run {
                /* KVM_EXIT_S390_SIEIC */
                struct {
                        __u8 icptcode;
-                       __u64 mask; /* psw upper half */
-                       __u64 addr; /* psw lower half */
                        __u16 ipa;
                        __u32 ipb;
                } s390_sieic;
@@ -492,6 +495,7 @@ struct kvm_ioeventfd {
 #ifdef __KVM_HAVE_VCPU_EVENTS
 #define KVM_CAP_VCPU_EVENTS 41
 #endif
+#define KVM_CAP_S390_PSW 42
 
 #ifdef KVM_CAP_IRQ_ROUTING