5 files changed, 282 insertions, 11 deletions

diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index c7b15f3e2cf3..76b6dbd627df 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -53,5 +53,5 @@ config XEN_DEBUG_FS
 
 config XEN_PVH
         bool "Support for running as a PVH guest"
-        depends on X86_64 && XEN && XEN_PVHVM
+        depends on XEN && XEN_PVHVM && ACPI
         def_bool n
diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
index e47e52787d32..cb0164aee156 100644
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -23,3 +23,4 @@ obj-$(CONFIG_XEN_DEBUG_FS)	+= debugfs.o
 obj-$(CONFIG_XEN_DOM0)          += vga.o
 obj-$(CONFIG_SWIOTLB_XEN)       += pci-swiotlb-xen.o
 obj-$(CONFIG_XEN_EFI)           += efi.o
+obj-$(CONFIG_XEN_PVH)           += xen-pvh.o
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 828f1b226f56..d2144f7c8fab 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -45,6 +45,7 @@
 #include <xen/interface/memory.h>
 #include <xen/interface/nmi.h>
 #include <xen/interface/xen-mca.h>
+#include <xen/interface/hvm/start_info.h>
 #include <xen/features.h>
 #include <xen/page.h>
 #include <xen/hvm.h>
@@ -176,6 +177,20 @@ struct tls_descs {
  */
 static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc);
 
+#ifdef CONFIG_XEN_PVH
+/*
+ * PVH variables.
+ *
+ * xen_pvh and pvh_bootparams need to live in data segment since they
+ * are used after startup_{32|64}, which clear .bss, are invoked.
+ */
+bool xen_pvh __attribute__((section(".data"))) = 0;
+struct boot_params pvh_bootparams __attribute__((section(".data")));
+
+struct hvm_start_info pvh_start_info;
+unsigned int pvh_start_info_sz = sizeof(pvh_start_info);
+#endif
+
 static void clamp_max_cpus(void)
 {
 #ifdef CONFIG_SMP
@@ -1656,6 +1671,90 @@ asmlinkage __visible void __init xen_start_kernel(void)
 #endif
 }
 
+#ifdef CONFIG_XEN_PVH
+static void __init init_pvh_bootparams(void)
+{
+        struct xen_memory_map memmap;
+        unsigned int i;
+        int rc;
+
+        memset(&pvh_bootparams, 0, sizeof(pvh_bootparams));
+
+        memmap.nr_entries = ARRAY_SIZE(pvh_bootparams.e820_map);
+        set_xen_guest_handle(memmap.buffer, pvh_bootparams.e820_map);
+        rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
+        if (rc) {
+                xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);
+                BUG();
+        }
+
+        if (memmap.nr_entries < E820MAX - 1) {
+                pvh_bootparams.e820_map[memmap.nr_entries].addr =
+                        ISA_START_ADDRESS;
+                pvh_bootparams.e820_map[memmap.nr_entries].size =
+                        ISA_END_ADDRESS - ISA_START_ADDRESS;
+                pvh_bootparams.e820_map[memmap.nr_entries].type =
+                        E820_RESERVED;
+                memmap.nr_entries++;
+        } else
+                xen_raw_printk("Warning: Can fit ISA range into e820\n");
+
+        sanitize_e820_map(pvh_bootparams.e820_map,
+                          ARRAY_SIZE(pvh_bootparams.e820_map),
+                          &memmap.nr_entries);
+
+        pvh_bootparams.e820_entries = memmap.nr_entries;
+        for (i = 0; i < pvh_bootparams.e820_entries; i++)
+                e820_add_region(pvh_bootparams.e820_map[i].addr,
+                                pvh_bootparams.e820_map[i].size,
+                                pvh_bootparams.e820_map[i].type);
+
+        pvh_bootparams.hdr.cmd_line_ptr =
+                pvh_start_info.cmdline_paddr;
+
+        /* The first module is always ramdisk. */
+        if (pvh_start_info.nr_modules) {
+                struct hvm_modlist_entry *modaddr =
+                        __va(pvh_start_info.modlist_paddr);
+                pvh_bootparams.hdr.ramdisk_image = modaddr->paddr;
+                pvh_bootparams.hdr.ramdisk_size = modaddr->size;
+        }
+
+        /*
+         * See Documentation/x86/boot.txt.
+         *
+         * Version 2.12 supports Xen entry point but we will use default x86/PC
+         * environment (i.e. hardware_subarch 0).
+         */
+        pvh_bootparams.hdr.version = 0x212;
+        pvh_bootparams.hdr.type_of_loader = (9 << 4) | 0; /* Xen loader */
+}
+
+/*
+ * This routine (and those that it might call) should not use
+ * anything that lives in .bss since that segment will be cleared later.
+ */
+void __init xen_prepare_pvh(void)
+{
+        u32 msr;
+        u64 pfn;
+
+        if (pvh_start_info.magic != XEN_HVM_START_MAGIC_VALUE) {
+                xen_raw_printk("Error: Unexpected magic value (0x%08x)\n",
+                                pvh_start_info.magic);
+                BUG();
+        }
+
+        xen_pvh = 1;
+
+        msr = cpuid_ebx(xen_cpuid_base() + 2);
+        pfn = __pa(hypercall_page);
+        wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
+
+        init_pvh_bootparams();
+}
+#endif
+
 void __ref xen_hvm_init_shared_info(void)
 {
         int cpu;
@@ -1695,20 +1794,29 @@ void __ref xen_hvm_init_shared_info(void)
 static void __init init_hvm_pv_info(void)
 {
         int major, minor;
-        uint32_t eax, ebx, ecx, edx, pages, msr, base;
-        u64 pfn;
+        uint32_t eax, ebx, ecx, edx, base;
 
         base = xen_cpuid_base();
-        cpuid(base + 1, &eax, &ebx, &ecx, &edx);
+        eax = cpuid_eax(base + 1);
 
         major = eax >> 16;
         minor = eax & 0xffff;
         printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
 
-        cpuid(base + 2, &pages, &msr, &ecx, &edx);
+        xen_domain_type = XEN_HVM_DOMAIN;
 
-        pfn = __pa(hypercall_page);
-        wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
+        /* PVH set up hypercall page in xen_prepare_pvh(). */
+        if (xen_pvh_domain())
+                pv_info.name = "Xen PVH";
+        else {
+                u64 pfn;
+                uint32_t msr;
+
+                pv_info.name = "Xen HVM";
+                msr = cpuid_ebx(base + 2);
+                pfn = __pa(hypercall_page);
+                wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
+        }
 
         xen_setup_features();
 
@@ -1717,10 +1825,6 @@ static void __init init_hvm_pv_info(void)
                 this_cpu_write(xen_vcpu_id, ebx);
         else
                 this_cpu_write(xen_vcpu_id, smp_processor_id());
-
-        pv_info.name = "Xen HVM";
-
-        xen_domain_type = XEN_HVM_DOMAIN;
 }
 #endif
 
diff --git a/arch/x86/xen/xen-pvh.S b/arch/x86/xen/xen-pvh.S
new file mode 100644
index 000000000000..5e246716d58f
--- /dev/null
+++ b/arch/x86/xen/xen-pvh.S
@@ -0,0 +1,161 @@
+/*
+ * Copyright C 2016, Oracle and/or its affiliates. All rights reserved.
+ *
+ * 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/>.
+ */
+
+        .code32
+        .text
+#define _pa(x)          ((x) - __START_KERNEL_map)
+
+#include <linux/elfnote.h>
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <asm/segment.h>
+#include <asm/asm.h>
+#include <asm/boot.h>
+#include <asm/processor-flags.h>
+#include <asm/msr.h>
+#include <xen/interface/elfnote.h>
+
+        __HEAD
+
+/*
+ * Entry point for PVH guests.
+ *
+ * Xen ABI specifies the following register state when we come here:
+ *
+ * - `ebx`: contains the physical memory address where the loader has placed
+ *          the boot start info structure.
+ * - `cr0`: bit 0 (PE) must be set. All the other writeable bits are cleared.
+ * - `cr4`: all bits are cleared.
+ * - `cs `: must be a 32-bit read/execute code segment with a base of ‘0’
+ *          and a limit of ‘0xFFFFFFFF’. The selector value is unspecified.
+ * - `ds`, `es`: must be a 32-bit read/write data segment with a base of
+ *               ‘0’ and a limit of ‘0xFFFFFFFF’. The selector values are all
+ *               unspecified.
+ * - `tr`: must be a 32-bit TSS (active) with a base of '0' and a limit
+ *         of '0x67'.
+ * - `eflags`: bit 17 (VM) must be cleared. Bit 9 (IF) must be cleared.
+ *             Bit 8 (TF) must be cleared. Other bits are all unspecified.
+ *
+ * All other processor registers and flag bits are unspecified. The OS is in
+ * charge of setting up it's own stack, GDT and IDT.
+ */
+
+ENTRY(pvh_start_xen)
+        cld
+
+        lgdt (_pa(gdt))
+
+        mov $(__BOOT_DS),%eax
+        mov %eax,%ds
+        mov %eax,%es
+        mov %eax,%ss
+
+        /* Stash hvm_start_info. */
+        mov $_pa(pvh_start_info), %edi
+        mov %ebx, %esi
+        mov _pa(pvh_start_info_sz), %ecx
+        shr $2,%ecx
+        rep
+        movsl
+
+        mov $_pa(early_stack_end), %esp
+
+        /* Enable PAE mode. */
+        mov %cr4, %eax
+        orl $X86_CR4_PAE, %eax
+        mov %eax, %cr4
+
+#ifdef CONFIG_X86_64
+        /* Enable Long mode. */
+        mov $MSR_EFER, %ecx
+        rdmsr
+        btsl $_EFER_LME, %eax
+        wrmsr
+
+        /* Enable pre-constructed page tables. */
+        mov $_pa(init_level4_pgt), %eax
+        mov %eax, %cr3
+        mov $(X86_CR0_PG | X86_CR0_PE), %eax
+        mov %eax, %cr0
+
+        /* Jump to 64-bit mode. */
+        ljmp $__KERNEL_CS, $_pa(1f)
+
+        /* 64-bit entry point. */
+        .code64
+1:
+        call xen_prepare_pvh
+
+        /* startup_64 expects boot_params in %rsi. */
+        mov $_pa(pvh_bootparams), %rsi
+        mov $_pa(startup_64), %rax
+        jmp *%rax
+
+#else /* CONFIG_X86_64 */
+
+        call mk_early_pgtbl_32
+
+        mov $_pa(initial_page_table), %eax
+        mov %eax, %cr3
+
+        mov %cr0, %eax
+        or $(X86_CR0_PG | X86_CR0_PE), %eax
+        mov %eax, %cr0
+
+        ljmp $__BOOT_CS, $1f
+1:
+        call xen_prepare_pvh
+        mov $_pa(pvh_bootparams), %esi
+
+        /* startup_32 doesn't expect paging and PAE to be on. */
+        ljmp $__BOOT_CS, $_pa(2f)
+2:
+        mov %cr0, %eax
+        and $~X86_CR0_PG, %eax
+        mov %eax, %cr0
+        mov %cr4, %eax
+        and $~X86_CR4_PAE, %eax
+        mov %eax, %cr4
+
+        ljmp $__BOOT_CS, $_pa(startup_32)
+#endif
+END(pvh_start_xen)
+
+        .section ".init.data","aw"
+        .balign 8
+gdt:
+        .word gdt_end - gdt_start
+        .long _pa(gdt_start)
+        .word 0
+gdt_start:
+        .quad 0x0000000000000000            /* NULL descriptor */
+        .quad 0x0000000000000000            /* reserved */
+#ifdef CONFIG_X86_64
+        .quad GDT_ENTRY(0xa09a, 0, 0xfffff) /* __KERNEL_CS */
+#else
+        .quad GDT_ENTRY(0xc09a, 0, 0xfffff) /* __KERNEL_CS */
+#endif
+        .quad GDT_ENTRY(0xc092, 0, 0xfffff) /* __KERNEL_DS */
+gdt_end:
+
+        .balign 4
+early_stack:
+        .fill 256, 1, 0
+early_stack_end:
+
+        ELFNOTE(Xen, XEN_ELFNOTE_PHYS32_ENTRY,
+                     _ASM_PTR (pvh_start_xen - __START_KERNEL_map))
diff --git a/include/xen/xen.h b/include/xen/xen.h
index d0f96840f71f..6e8b7fc79801 100644
--- a/include/xen/xen.h
+++ b/include/xen/xen.h
@@ -29,6 +29,11 @@ extern enum xen_domain_type xen_domain_type;
 #define xen_initial_domain()    (0)
 #endif  /* CONFIG_XEN_DOM0 */
 
+#ifdef CONFIG_XEN_PVH
+extern bool xen_pvh;
+#define xen_pvh_domain()        (xen_hvm_domain() && xen_pvh)
+#else
 #define xen_pvh_domain()        (0)
+#endif
 
 #endif  /* _XEN_XEN_H */