x86/entry: Early PVH boot code

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

xen/arch/x86/Makefile

@@ -1,6 +1,7 @@
 subdir-y += acpi
 subdir-y += cpu
 subdir-y += genapic
+subdir-$(CONFIG_XEN_GUEST) += guest
 subdir-$(CONFIG_HVM) += hvm
 subdir-y += mm
 subdir-$(CONFIG_XENOPROF) += oprofile

xen/arch/x86/boot/head.S

@@ -379,7 +379,39 @@ cs32_switch:
 ELFNOTE(Xen, XEN_ELFNOTE_PHYS32_ENTRY, .long sym_offs(__pvh_start))
 
 __pvh_start:
-        ud2a
+        cld
+        cli
+
+        /*
+         * We need one push/pop to determine load address.  Use the same
+         * absolute stack address as the native path, for lack of a better
+         * alternative.
+         */
+        mov     $0x1000, %esp
+
+        /* Calculate the load base address. */
+        call    1f
+1:      pop     %esi
+        sub     $sym_offs(1b), %esi
+
+        /* Set up stack. */
+        lea     STACK_SIZE + sym_esi(cpu0_stack), %esp
+
+        mov     %ebx, sym_esi(pvh_start_info_pa)
+
+        /* Prepare gdt and segments */
+        add     %esi, sym_esi(gdt_boot_base)
+        lgdt    sym_esi(gdt_boot_descr)
+
+        mov     $BOOT_DS, %ecx
+        mov     %ecx, %ds
+        mov     %ecx, %es
+        mov     %ecx, %ss
+
+        /* Skip bootloader setup and bios setup, go straight to trampoline */
+        movb    $1, sym_esi(pvh_boot)
+        movb    $1, sym_esi(skip_realmode)
+        jmp     trampoline_setup
 
 #endif /* CONFIG_PVH_GUEST */
 
@@ -543,12 +575,18 @@ trampoline_setup:
         /* Get bottom-most low-memory stack address. */
         add     $TRAMPOLINE_SPACE,%ecx
 
+#ifdef CONFIG_PVH_GUEST
+        cmpb    $0, sym_fs(pvh_boot)
+        jne     1f
+#endif
+
         /* Save the Multiboot info struct (after relocation) for later use. */
         push    %ecx                /* Bottom-most low-memory stack address. */
         push    %ebx                /* Multiboot information address. */
         push    %eax                /* Multiboot magic. */
         call    reloc
         mov     %eax,sym_fs(multiboot_ptr)
+1:
 
         /*
          * Now trampoline_phys points to the following structure (lowest address

xen/arch/x86/boot/x86_64.S

@@ -31,7 +31,7 @@ ENTRY(__high_start)
         test    %ebx,%ebx
         jnz     start_secondary
 
-        /* Pass off the Multiboot info structure to C land. */
+        /* Pass off the Multiboot info structure to C land (if applicable). */
         mov     multiboot_ptr(%rip),%edi
         call    __start_xen
         BUG     /* __start_xen() shouldn't return. */

xen/arch/x86/guest/Makefile

@@ -0,0 +1 @@
+obj-bin-$(CONFIG_PVH_GUEST) += pvh-boot.init.o

xen/arch/x86/guest/pvh-boot.c

@@ -0,0 +1,119 @@
+/******************************************************************************
+ * arch/x86/guest/pvh-boot.c
+ *
+ * PVH boot time support
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that 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/>.
+ *
+ * Copyright (c) 2017 Citrix Systems Ltd.
+ */
+#include <xen/init.h>
+#include <xen/lib.h>
+#include <xen/mm.h>
+
+#include <asm/guest.h>
+
+#include <public/arch-x86/hvm/start_info.h>
+
+/* Initialised in head.S, before .bss is zeroed. */
+bool __initdata pvh_boot;
+uint32_t __initdata pvh_start_info_pa;
+
+static multiboot_info_t __initdata pvh_mbi;
+static module_t __initdata pvh_mbi_mods[8];
+static const char *__initdata pvh_loader = "PVH Directboot";
+
+static void __init convert_pvh_info(void)
+{
+    const struct hvm_start_info *pvh_info = __va(pvh_start_info_pa);
+    const struct hvm_modlist_entry *entry;
+    module_t *mod;
+    unsigned int i;
+
+    ASSERT(pvh_info->magic == XEN_HVM_START_MAGIC_VALUE);
+
+    /*
+     * Turn hvm_start_info into mbi. Luckily all modules are placed under 4GB
+     * boundary on x86.
+     */
+    pvh_mbi.flags = MBI_CMDLINE | MBI_MODULES | MBI_LOADERNAME;
+
+    BUG_ON(pvh_info->cmdline_paddr >> 32);
+    pvh_mbi.cmdline = pvh_info->cmdline_paddr;
+    pvh_mbi.boot_loader_name = __pa(pvh_loader);
+
+    BUG_ON(pvh_info->nr_modules >= ARRAY_SIZE(pvh_mbi_mods));
+    pvh_mbi.mods_count = pvh_info->nr_modules;
+    pvh_mbi.mods_addr = __pa(pvh_mbi_mods);
+
+    mod = pvh_mbi_mods;
+    entry = __va(pvh_info->modlist_paddr);
+    for ( i = 0; i < pvh_info->nr_modules; i++ )
+    {
+        BUG_ON(entry[i].paddr >> 32);
+        BUG_ON(entry[i].cmdline_paddr >> 32);
+
+        mod[i].mod_start = entry[i].paddr;
+        mod[i].mod_end   = entry[i].paddr + entry[i].size;
+        mod[i].string    = entry[i].cmdline_paddr;
+    }
+}
+
+multiboot_info_t *__init pvh_init(void)
+{
+    convert_pvh_info();
+
+    return &pvh_mbi;
+}
+
+void __init pvh_print_info(void)
+{
+    const struct hvm_start_info *pvh_info = __va(pvh_start_info_pa);
+    const struct hvm_modlist_entry *entry;
+    unsigned int i;
+
+    ASSERT(pvh_info->magic == XEN_HVM_START_MAGIC_VALUE);
+
+    printk("PVH start info: (pa %08x)\n", pvh_start_info_pa);
+    printk("  version:    %u\n", pvh_info->version);
+    printk("  flags:      %#"PRIx32"\n", pvh_info->flags);
+    printk("  nr_modules: %u\n", pvh_info->nr_modules);
+    printk("  modlist_pa: %016"PRIx64"\n", pvh_info->modlist_paddr);
+    printk("  cmdline_pa: %016"PRIx64"\n", pvh_info->cmdline_paddr);
+    if ( pvh_info->cmdline_paddr )
+        printk("  cmdline:    '%s'\n", (char *)__va(pvh_info->cmdline_paddr));
+    printk("  rsdp_pa:    %016"PRIx64"\n", pvh_info->rsdp_paddr);
+
+    entry = __va(pvh_info->modlist_paddr);
+    for ( i = 0; i < pvh_info->nr_modules; i++ )
+    {
+        printk("    mod[%u].pa:         %016"PRIx64"\n", i, entry[i].paddr);
+        printk("    mod[%u].size:       %016"PRIu64"\n", i, entry[i].size);
+        printk("    mod[%u].cmdline_pa: %016"PRIx64"\n",
+               i, entry[i].cmdline_paddr);
+        if ( entry[i].cmdline_paddr )
+            printk("    mod[%1u].cmdline:    '%s'\n", i,
+                   (char *)__va(entry[i].cmdline_paddr));
+    }
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */

xen/arch/x86/setup.c

@@ -52,6 +52,7 @@
 #include <asm/mc146818rtc.h>
 #include <asm/cpuid.h>
 #include <asm/spec_ctrl.h>
+#include <asm/guest.h>
 
 /* opt_nosmp: If true, secondary processors are ignored. */
 static bool __initdata opt_nosmp;
@@ -650,8 +651,8 @@ void __init noreturn __start_xen(unsigned long mbi_p)
     char *memmap_type = NULL;
     char *cmdline, *kextra, *loader;
     unsigned int initrdidx, domcr_flags = DOMCRF_s3_integrity;
-    multiboot_info_t *mbi = __va(mbi_p);
-    module_t *mod = (module_t *)__va(mbi->mods_addr);
+    multiboot_info_t *mbi;
+    module_t *mod;
     unsigned long nr_pages, raw_max_page, modules_headroom, *module_map;
     int i, j, e820_warn = 0, bytes = 0;
     bool acpi_boot_table_init_done = false, relocated = false;
@@ -681,6 +682,16 @@ void __init noreturn __start_xen(unsigned long mbi_p)
 
     /* Full exception support from here on in. */
 
+    if ( pvh_boot )
+    {
+        ASSERT(mbi_p == 0);
+        mbi = pvh_init();
+    }
+    else
+        mbi = __va(mbi_p);
+
+    mod = __va(mbi->mods_addr);
+
     loader = (mbi->flags & MBI_LOADERNAME)
         ? (char *)__va(mbi->boot_loader_name) : "unknown";
 
@@ -720,6 +731,9 @@ void __init noreturn __start_xen(unsigned long mbi_p)
     ehci_dbgp_init();
     console_init_preirq();
 
+    if ( pvh_boot )
+        pvh_print_info();
+
     printk("Bootloader: %s\n", loader);
 
     printk("Command line: %s\n", cmdline);

xen/include/asm-x86/guest.h

@@ -0,0 +1,34 @@
+/******************************************************************************
+ * asm-x86/guest.h
+ *
+ * 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 that 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/>.
+ *
+ * Copyright (c) 2017 Citrix Systems Ltd.
+ */
+
+#ifndef __X86_GUEST_H__
+#define __X86_GUEST_H__
+
+#include <asm/guest/pvh-boot.h>
+
+#endif /* __X86_GUEST_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */

xen/include/asm-x86/guest/pvh-boot.h

@@ -0,0 +1,57 @@
+/******************************************************************************
+ * asm-x86/guest/pvh-boot.h
+ *
+ * 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 that 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/>.
+ *
+ * Copyright (c) 2017 Citrix Systems Ltd.
+ */
+
+#ifndef __X86_PVH_BOOT_H__
+#define __X86_PVH_BOOT_H__
+
+#include <xen/multiboot.h>
+
+#ifdef CONFIG_PVH_GUEST
+
+extern bool pvh_boot;
+
+multiboot_info_t *pvh_init(void);
+void pvh_print_info(void);
+
+#else
+
+#define pvh_boot 0
+
+static inline multiboot_info_t *pvh_init(void)
+{
+    ASSERT_UNREACHABLE();
+    return NULL;
+}
+
+static inline void pvh_print_info(void)
+{
+    ASSERT_UNREACHABLE();
+}
+
+#endif /* CONFIG_PVH_GUEST */
+#endif /* __X86_PVH_BOOT_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */