KVM: s390: arch backend for the kvm kernel module

This patch contains the port of Qumranet's kvm kernel module to IBM zSeries
 (aka s390x, mainframe) architecture. It uses the mainframe's virtualization
instruction SIE to run virtual machines with up to 64 virtual CPUs each.
This port is only usable on 64bit host kernels, and can only run 64bit guest
kernels. However, running 31bit applications in guest userspace is possible.

The following source files are introduced by this patch
arch/s390/kvm/kvm-s390.c    similar to arch/x86/kvm/x86.c, this implements all
                            arch callbacks for kvm. __vcpu_run calls back into
                            sie64a to enter the guest machine context
arch/s390/kvm/sie64a.S      assembler function sie64a, which enters guest
                            context via SIE, and switches world before and after                            that
include/asm-s390/kvm_host.h contains all vital data structures needed to run
                            virtual machines on the mainframe
include/asm-s390/kvm.h      defines kvm_regs and friends for user access to
                            guest register content
arch/s390/kvm/gaccess.h     functions similar to uaccess to access guest memory
arch/s390/kvm/kvm-s390.h    header file for kvm-s390 internals, extended by
                            later patches

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 127 insertions, 0 deletions

diff --git a/include/asm-s390/kvm_host.h b/include/asm-s390/kvm_host.h
new file mode 100644
index 000000000000..c9d653333106
--- /dev/null
+++ b/include/asm-s390/kvm_host.h
@@ -0,0 +1,127 @@
+/*
+ * asm-s390/kvm_host.h - definition for kernel virtual machines on s390
+ *
+ * Copyright IBM Corp. 2008
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ *
+ *    Author(s): Carsten Otte <cotte@de.ibm.com>
+ */
+
+
+#ifndef ASM_KVM_HOST_H
+#define ASM_KVM_HOST_H
+#include <linux/kvm_host.h>
+#include <asm/debug.h>
+
+#define KVM_MAX_VCPUS 64
+#define KVM_MEMORY_SLOTS 32
+/* memory slots that does not exposed to userspace */
+#define KVM_PRIVATE_MEM_SLOTS 4
+
+struct kvm_guest_debug {
+};
+
+struct sca_entry {
+        atomic_t scn;
+        __u64   reserved;
+        __u64   sda;
+        __u64   reserved2[2];
+} __attribute__((packed));
+
+
+struct sca_block {
+        __u64   ipte_control;
+        __u64   reserved[5];
+        __u64   mcn;
+        __u64   reserved2;
+        struct sca_entry cpu[64];
+} __attribute__((packed));
+
+#define KVM_PAGES_PER_HPAGE 256
+
+#define CPUSTAT_HOST       0x80000000
+#define CPUSTAT_WAIT       0x10000000
+#define CPUSTAT_ECALL_PEND 0x08000000
+#define CPUSTAT_STOP_INT   0x04000000
+#define CPUSTAT_IO_INT     0x02000000
+#define CPUSTAT_EXT_INT    0x01000000
+#define CPUSTAT_RUNNING    0x00800000
+#define CPUSTAT_RETAINED   0x00400000
+#define CPUSTAT_TIMING_SUB 0x00020000
+#define CPUSTAT_SIE_SUB    0x00010000
+#define CPUSTAT_RRF        0x00008000
+#define CPUSTAT_SLSV       0x00004000
+#define CPUSTAT_SLSR       0x00002000
+#define CPUSTAT_ZARCH      0x00000800
+#define CPUSTAT_MCDS       0x00000100
+#define CPUSTAT_SM         0x00000080
+#define CPUSTAT_G          0x00000008
+#define CPUSTAT_J          0x00000002
+#define CPUSTAT_P          0x00000001
+
+struct sie_block {
+        atomic_t cpuflags;              /* 0x0000 */
+        __u32   prefix;                 /* 0x0004 */
+        __u8    reserved8[32];          /* 0x0008 */
+        __u64   cputm;                  /* 0x0028 */
+        __u64   ckc;                    /* 0x0030 */
+        __u64   epoch;                  /* 0x0038 */
+        __u8    reserved40[4];          /* 0x0040 */
+        __u16   lctl;                   /* 0x0044 */
+        __s16   icpua;                  /* 0x0046 */
+        __u32   ictl;                   /* 0x0048 */
+        __u32   eca;                    /* 0x004c */
+        __u8    icptcode;               /* 0x0050 */
+        __u8    reserved51;             /* 0x0051 */
+        __u16   ihcpu;                  /* 0x0052 */
+        __u8    reserved54[2];          /* 0x0054 */
+        __u16   ipa;                    /* 0x0056 */
+        __u32   ipb;                    /* 0x0058 */
+        __u32   scaoh;                  /* 0x005c */
+        __u8    reserved60;             /* 0x0060 */
+        __u8    ecb;                    /* 0x0061 */
+        __u8    reserved62[2];          /* 0x0062 */
+        __u32   scaol;                  /* 0x0064 */
+        __u8    reserved68[4];          /* 0x0068 */
+        __u32   todpr;                  /* 0x006c */
+        __u8    reserved70[16];         /* 0x0070 */
+        __u64   gmsor;                  /* 0x0080 */
+        __u64   gmslm;                  /* 0x0088 */
+        psw_t   gpsw;                   /* 0x0090 */
+        __u64   gg14;                   /* 0x00a0 */
+        __u64   gg15;                   /* 0x00a8 */
+        __u8    reservedb0[80];         /* 0x00b0 */
+        __u64   gcr[16];                /* 0x0100 */
+        __u64   gbea;                   /* 0x0180 */
+        __u8    reserved188[120];       /* 0x0188 */
+} __attribute__((packed));
+
+struct kvm_vcpu_stat {
+        u32 exit_userspace;
+};
+
+struct kvm_vcpu_arch {
+        struct sie_block *sie_block;
+        unsigned long     guest_gprs[16];
+        s390_fp_regs      host_fpregs;
+        unsigned int      host_acrs[NUM_ACRS];
+        s390_fp_regs      guest_fpregs;
+        unsigned int      guest_acrs[NUM_ACRS];
+};
+
+struct kvm_vm_stat {
+        u32 remote_tlb_flush;
+};
+
+struct kvm_arch{
+        unsigned long guest_origin;
+        unsigned long guest_memsize;
+        struct sca_block *sca;
+        debug_info_t *dbf;
+};
+
+extern int sie64a(struct sie_block *, __u64 *);
+#endif