[PATCH RFC XEN v1 07/14] xen: arm: Save and restore basic per-VCPU state.

[Ian Campbell <ian.campbell@citrix.com>]

XXX TBD No support for arm64 (or even 32-bit guest on arm64).
XXX In particular the handling of save/restore of VFP state doesn't
XXX even compile for arm32. I need to investigate the best way to
XXX reflect the differing possible VFB states in the save record.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
---
 xen/arch/arm/hvm.c                     | 167 +++++++++++++++++++++++++++++++++
 xen/include/public/arch-arm/hvm/save.h |  38 +++++++-
 2 files changed, 204 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/hvm.c b/xen/arch/arm/hvm.c
index 5fd0753..3c59e63 100644
--- a/xen/arch/arm/hvm.c
+++ b/xen/arch/arm/hvm.c
@@ -7,6 +7,7 @@
 
 #include <xsm/xsm.h>
 
+#include <xen/hvm/save.h>
 #include <public/xen.h>
 #include <public/hvm/params.h>
 #include <public/hvm/hvm_op.h>
@@ -65,3 +66,169 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) arg)
 
     return rc;
 }
+
+static int cpu_save(struct domain *d, hvm_domain_context_t *h)
+{
+    struct hvm_hw_cpu ctxt;
+    struct vcpu *v;
+
+    /* Save the state of CPU */
+    for_each_vcpu( d, v )
+    {
+        /*
+         * We don't need to save state for a vcpu that is down; the restore
+         * code will leave it down if there is nothing saved.
+         */
+        if ( test_bit(_VPF_down, &v->pause_flags) )
+            continue;
+
+        memset(&ctxt, 0, sizeof(ctxt));
+        ctxt.sctlr = v->arch.sctlr;
+        ctxt.ttbr0 = v->arch.ttbr0;
+        ctxt.ttbr1 = v->arch.ttbr1;
+        ctxt.ttbcr = v->arch.ttbcr;
+
+        ctxt.dacr = v->arch.dacr;
+#ifdef CONFIG_ARM_32 /* XXX 32on64 */
+        ctxt.ifar = v->arch.ifar;
+        ctxt.ifsr = v->arch.ifsr;
+        ctxt.dfar = v->arch.dfar;
+        ctxt.dfsr = v->arch.dfsr;
+#else
+        /* XXX 64-bit */
+#endif
+
+#ifdef CONFIG_ARM_32
+        ctxt.mair0 = v->arch.mair0;
+        ctxt.mair1 = v->arch.mair1;
+#else
+        ctxt.mair0 = v->arch.mair;
+#endif
+        /* Control Registers */
+        ctxt.actlr = v->arch.actlr;
+        ctxt.sctlr = v->arch.sctlr;
+        ctxt.cpacr = v->arch.cpacr;
+
+        ctxt.contextidr = v->arch.contextidr;
+        ctxt.tpidr_el0 = v->arch.tpidr_el0;
+        ctxt.tpidr_el1 = v->arch.tpidr_el1;
+        ctxt.tpidrro_el0 = v->arch.tpidrro_el0;
+
+        /* CP 15 */
+        ctxt.csselr = v->arch.csselr;
+        ctxt.mpidr = v->arch.vmpidr;
+
+        ctxt.afsr0 = v->arch.afsr0;
+        ctxt.afsr1 = v->arch.afsr1;
+        ctxt.vbar = v->arch.vbar;
+        ctxt.par = v->arch.par;
+        ctxt.teecr = v->arch.teecr;
+        ctxt.teehbr = v->arch.teehbr;
+#ifdef CONFIG_ARM_32 /* XXX 32on64 */
+        ctxt.joscr = v->arch.joscr;
+        ctxt.jmcr = v->arch.jmcr;
+#endif
+
+        memset(&ctxt.core_regs, 0, sizeof(ctxt.core_regs));
+
+        /* get guest core registers */
+        vcpu_regs_hyp_to_user(v, &ctxt.core_regs);
+
+        /* check VFP state size before dumping */
+        BUILD_BUG_ON(sizeof(v->arch.vfp) > sizeof (ctxt.vfp));
+        memcpy((void*) &ctxt.vfp, (void*) &v->arch.vfp, sizeof(v->arch.vfp));
+
+        if ( hvm_save_entry(VCPU, v->vcpu_id, h, &ctxt) != 0 )
+            return 1;
+    }
+    return 0;
+}
+
+static int cpu_load(struct domain *d, hvm_domain_context_t *h)
+{
+    int vcpuid;
+    struct hvm_hw_cpu ctxt;
+    struct vcpu *v;
+
+    /* Which vcpu is this? */
+    vcpuid = hvm_load_instance(h);
+    if ( vcpuid >= d->max_vcpus || (v = d->vcpu[vcpuid]) == NULL )
+    {
+        dprintk(XENLOG_G_ERR, "HVM restore: dom%u has no vcpu%u\n",
+                d->domain_id, vcpuid);
+        return -EINVAL;
+    }
+
+    if ( hvm_load_entry(VCPU, h, &ctxt) != 0 )
+        return -EINVAL;
+
+    v->arch.sctlr = ctxt.sctlr;
+    v->arch.ttbr0 = ctxt.ttbr0;
+    v->arch.ttbr1 = ctxt.ttbr1;
+    v->arch.ttbcr = ctxt.ttbcr;
+
+    v->arch.dacr = ctxt.dacr;
+#ifdef CONFIG_ARM_32 /* XXX 32on64 */
+    v->arch.ifar = ctxt.ifar;
+    v->arch.ifsr = ctxt.ifsr;
+    v->arch.dfar = ctxt.dfar;
+    v->arch.dfsr = ctxt.dfsr;
+#else
+    /* XXX 64-bit */
+#endif
+
+#ifdef CONFIG_ARM_32
+    v->arch.mair0 = ctxt.mair0;
+    v->arch.mair1 = ctxt.mair1;
+#else
+    v->arch.mair = ctxt.mair0;
+#endif
+
+    /* Control Registers */
+    v->arch.actlr = ctxt.actlr;
+    v->arch.cpacr = ctxt.cpacr;
+    v->arch.contextidr = ctxt.contextidr;
+    v->arch.tpidr_el0 = ctxt.tpidr_el0;
+    v->arch.tpidr_el1 = ctxt.tpidr_el1;
+    v->arch.tpidrro_el0 = ctxt.tpidrro_el0;
+
+    /* CP 15 */
+    v->arch.csselr = ctxt.csselr;
+    v->arch.vmpidr = ctxt.mpidr;
+
+    v->arch.afsr0 = ctxt.afsr0;
+    v->arch.afsr1 = ctxt.afsr1;
+    v->arch.vbar = ctxt.vbar;
+    v->arch.par = ctxt.par;
+    v->arch.teecr = ctxt.teecr;
+    v->arch.teehbr = ctxt.teehbr;
+#ifdef CONFIG_ARM_32 /* XXX 32on64 */
+    v->arch.joscr = ctxt.joscr;
+    v->arch.jmcr = ctxt.jmcr;
+#endif
+
+    /* set guest core registers */
+    vcpu_regs_user_to_hyp(v, &ctxt.core_regs);
+
+    /* restore VFP */
+    BUILD_BUG_ON(sizeof(v->arch.vfp) > sizeof (ctxt.vfp));
+    memcpy(&v->arch.vfp, &ctxt.vfp,  sizeof(v->arch.vfp));
+
+    v->is_initialised = 1;
+    clear_bit(_VPF_down, &v->pause_flags);
+
+    /* we don't need vcpu_wake(v) here */
+    return 0;
+}
+
+HVM_REGISTER_SAVE_RESTORE(VCPU, cpu_save, cpu_load, 1, HVMSR_PER_VCPU);
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/include/public/arch-arm/hvm/save.h b/xen/include/public/arch-arm/hvm/save.h
index 6f1be37..72474e5 100644
--- a/xen/include/public/arch-arm/hvm/save.h
+++ b/xen/include/public/arch-arm/hvm/save.h
@@ -44,10 +44,46 @@ struct hvm_save_header
 
 DECLARE_HVM_SAVE_TYPE(HEADER, 1, struct hvm_save_header);
 
+struct hvm_hw_cpu
+{
+    uint64_t vfp[34]; /* Vector floating pointer */
+    /* VFP v3 state is 34x64 bit, VFP v4 is not yet supported */
+
+    /* Guest core registers */
+    struct vcpu_guest_core_regs core_regs;
+
+    uint32_t sctlr, ttbcr;
+    uint64_t ttbr0, ttbr1;
+
+    uint32_t ifar, dfar;
+    uint32_t ifsr, dfsr;
+    uint32_t dacr;
+    uint64_t par;
+
+    uint64_t mair0, mair1;
+    uint64_t tpidr_el0;
+    uint64_t tpidr_el1;
+    uint64_t tpidrro_el0;
+    uint64_t vbar;
+
+    /* Control Registers */
+    uint32_t actlr;
+    uint32_t cpacr;
+    uint32_t afsr0, afsr1;
+    uint32_t contextidr;
+    uint32_t teecr, teehbr; /* ThumbEE, 32-bit guests only */
+    uint32_t joscr, jmcr;
+    /* CP 15 */
+    uint32_t csselr;
+    uint64_t mpidr;
+};
+
+DECLARE_HVM_SAVE_TYPE(VCPU, 2, struct hvm_hw_cpu);
+
 /*
  * Largest type-code in use
  */
-#define HVM_SAVE_CODE_MAX 1
+#define HVM_SAVE_CODE_MAX 2
 
 #endif
 
-- 
2.6.1