xen/pvh: Bootstrap PVH guest (7243b933) · Commits · 戴 / test

arch/x86/xen/Kconfig

+1 −1

Original line number	Diff line number	Diff line
		@@ -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

arch/x86/xen/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

arch/x86/xen/enlighten.c

+114 −10

Original line number	Diff line number	Diff line
		@@ -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;

		/* 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

arch/x86/xen/xen-pvh.S

0 → 100644

+161 −0

Original line number	Diff line number	Diff line
		/*
		* 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))

include/xen/xen.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -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 */

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