[PATCH RFC XEN v1 05/14] xen: arm: Implement basic XEN_DOMCTL_{set, get}hvmcontext support

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

This is just the minimally required basic infra and header, no actual
useful data is saved yet.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
---
 xen/arch/arm/Makefile                  |  1 +
 xen/arch/arm/domctl.c                  | 74 ++++++++++++++++++++++++++++++++++
 xen/arch/arm/save.c                    | 53 ++++++++++++++++++++++++
 xen/common/Makefile                    |  2 +
 xen/include/asm-arm/hvm/support.h      | 25 ++++++++++++
 xen/include/public/arch-arm/hvm/save.h | 17 ++++++++
 6 files changed, 172 insertions(+)
 create mode 100644 xen/arch/arm/save.c
 create mode 100644 xen/include/asm-arm/hvm/support.h

diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index 4ac5edd..5a96486 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -40,6 +40,7 @@ obj-y += device.o
 obj-y += decode.o
 obj-y += processor.o
 obj-y += smc.o
+obj-y += save.o
 
 #obj-bin-y += ....o
 
diff --git a/xen/arch/arm/domctl.c b/xen/arch/arm/domctl.c
index d3459ee..3403e23 100644
--- a/xen/arch/arm/domctl.c
+++ b/xen/arch/arm/domctl.c
@@ -12,6 +12,7 @@
 #include <xen/hypercall.h>
 #include <xen/iocap.h>
 #include <xsm/xsm.h>
+#include <xen/hvm/save.h>
 #include <xen/guest_access.h>
 #include <public/domctl.h>
 
@@ -134,6 +135,79 @@ long arch_do_domctl(struct xen_domctl *domctl, struct domain *d,
         break;
     }
 
+    case XEN_DOMCTL_sethvmcontext:
+    {
+        struct hvm_domain_context c = { .size = domctl->u.hvmcontext.size };
+
+        if ( (c.data = xmalloc_bytes(c.size)) == NULL )
+        {
+            rc = -ENOMEM;
+            goto sethvmcontext_out;
+        }
+
+        if ( copy_from_guest(c.data, domctl->u.hvmcontext.buffer, c.size) != 0 )
+        {
+            rc = -EFAULT;
+            goto sethvmcontext_out;
+        }
+
+        domain_pause(d);
+        rc = hvm_load(d, &c);
+        domain_unpause(d);
+
+    sethvmcontext_out:
+        if ( c.data != NULL )
+            xfree(c.data);
+
+        break;
+
+    }
+    case XEN_DOMCTL_gethvmcontext:
+    {
+        struct hvm_domain_context c = { 0 };
+
+        c.size = hvm_save_size(d);
+
+        if ( guest_handle_is_null(domctl->u.hvmcontext.buffer) )
+        {
+            /* Client is querying for the correct buffer size */
+            domctl->u.hvmcontext.size = c.size;
+            rc = 0;
+            goto gethvmcontext_out;
+        }
+
+        /* Check that the client has a big enough buffer */
+        if ( domctl->u.hvmcontext.size < c.size )
+        {
+            rc = -ENOSPC;
+            goto gethvmcontext_out;
+        }
+
+        /* Allocate our own marshalling buffer */
+        if ( (c.data = xmalloc_bytes(c.size)) == NULL )
+        {
+            rc = -ENOMEM;
+            goto gethvmcontext_out;
+        }
+
+        domain_pause(d);
+        rc = hvm_save(d, &c);
+        domain_unpause(d);
+
+        domctl->u.hvmcontext.size = c.cur;
+        if ( copy_to_guest(domctl->u.hvmcontext.buffer, c.data, c.size) != 0 )
+            rc = -EFAULT;
+        else
+            rc = 0;
+
+    gethvmcontext_out:
+        copyback = 1;
+
+        if ( c.data != NULL )
+            xfree(c.data);
+    }
+    break;
+
    case XEN_DOMCTL_getpageframeinfo3:
     {
         unsigned int i;
diff --git a/xen/arch/arm/save.c b/xen/arch/arm/save.c
new file mode 100644
index 0000000..6a1934b
--- /dev/null
+++ b/xen/arch/arm/save.c
@@ -0,0 +1,53 @@
+/*
+ * hvm/save.c: Save and restore HVM guest's emulated hardware state for ARM.
+ *
+ * Copyright (c) 2013, Samsung Electronics.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <asm/hvm/support.h>
+#include <public/hvm/save.h>
+
+void arch_hvm_save(struct domain *d, struct hvm_save_header *hdr)
+{
+}
+
+int arch_hvm_load(struct domain *d, struct hvm_save_header *hdr)
+{
+    if ( hdr->magic != HVM_FILE_MAGIC )
+    {
+        printk(XENLOG_G_ERR "HVM%d restore: bad magic number %#"PRIx32"\n",
+               d->domain_id, hdr->magic);
+        return -1;
+    }
+
+    if ( hdr->version != HVM_FILE_VERSION )
+    {
+        printk(XENLOG_G_ERR "HVM%d restore: unsupported version %u\n",
+               d->domain_id, hdr->version);
+        return -1;
+    }
+
+    return 0;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/common/Makefile b/xen/common/Makefile
index 3547c8e..ce8078f 100644
--- a/xen/common/Makefile
+++ b/xen/common/Makefile
@@ -67,6 +67,8 @@ obj-$(CONFIG_COMPAT) += $(addprefix compat/,domain.o kernel.o memory.o multicall
 
 subdir-$(x86_64) += hvm
 
+subdir-$(CONFIG_ARM) += hvm
+
 subdir-$(coverage) += gcov
 
 subdir-y += libelf
diff --git a/xen/include/asm-arm/hvm/support.h b/xen/include/asm-arm/hvm/support.h
new file mode 100644
index 0000000..842d8a3
--- /dev/null
+++ b/xen/include/asm-arm/hvm/support.h
@@ -0,0 +1,25 @@
+/*
+ * support.h: HVM support routines used by ARM.
+ *
+ * Copyright (c) 2013, Samsung Electronics
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __ASM_ARM_HVM_SUPPORT_H__
+#define __ASM_ARM_HVM_SUPPORT_H__
+
+#include <xen/sched.h>
+#include <xen/hvm/save.h>
+
+#endif /* __ASM_ARM_HVM_SUPPORT_H__ */
diff --git a/xen/include/public/arch-arm/hvm/save.h b/xen/include/public/arch-arm/hvm/save.h
index 75b8e65..5f4de94 100644
--- a/xen/include/public/arch-arm/hvm/save.h
+++ b/xen/include/public/arch-arm/hvm/save.h
@@ -26,6 +26,23 @@
 #ifndef __XEN_PUBLIC_HVM_SAVE_ARM_H__
 #define __XEN_PUBLIC_HVM_SAVE_ARM_H__
 
+#define HVM_FILE_MAGIC   0x92385520
+#define HVM_FILE_VERSION 0x00000001
+
+struct hvm_save_header
+{
+    uint32_t magic;             /* Must be HVM_FILE_MAGIC */
+    uint32_t version;           /* File format version */
+    uint64_t changeset;         /* Version of Xen that saved this file */
+};
+
+DECLARE_HVM_SAVE_TYPE(HEADER, 1, struct hvm_save_header);
+
+/*
+ * Largest type-code in use
+ */
+#define HVM_SAVE_CODE_MAX 1
+
 #endif
 
 /*
-- 
2.6.1