Merge tag 'for-linus-4.21-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:
 "Xen features and fixes:

   - a series to enable KVM guests to be booted by qemu via the Xen PVH
     boot entry for speeding up KVM guest tests

   - a series for a common driver to be used by Xen PV frontends (right
     now drm and sound)

   - two other fixes in Xen related code"

* tag 'for-linus-4.21-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  ALSA: xen-front: Use Xen common shared buffer implementation
  drm/xen-front: Use Xen common shared buffer implementation
  xen: Introduce shared buffer helpers for page directory...
  xen/pciback: Check dev_data before using it
  kprobes/x86/xen: blacklist non-attachable xen interrupt functions
  KVM: x86: Allow Qemu/KVM to use PVH entry point
  xen/pvh: Add memory map pointer to hvm_start_info struct
  xen/pvh: Move Xen code for getting mem map via hcall out of common file
  xen/pvh: Move Xen specific PVH VM initialization out of common file
  xen/pvh: Create a new file for Xen specific PVH code
  xen/pvh: Move PVH entry code out of Xen specific tree
  xen/pvh: Split CONFIG_XEN_PVH into CONFIG_PVH and CONFIG_XEN_PVH

5 files changed, 21 insertions, 255 deletions

diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index 1ef391aa184d..e07abefd3d26 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -74,6 +74,7 @@ config XEN_DEBUG_FS
 	  Enabling this option may incur a significant performance overhead.
 
 config XEN_PVH
-	bool "Support for running as a PVH guest"
+	bool "Support for running as a Xen PVH guest"
 	depends on XEN && XEN_PVHVM && ACPI
+	select PVH
 	def_bool n
diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
index dd2550d33b38..084de77a109e 100644
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -1,6 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
 OBJECT_FILES_NON_STANDARD_xen-asm_$(BITS).o := y
-OBJECT_FILES_NON_STANDARD_xen-pvh.o := y
 
 ifdef CONFIG_FUNCTION_TRACER
 # Do not profile debug and lowlevel utilities
@@ -38,7 +37,6 @@ obj-$(CONFIG_XEN_PV)		+= xen-asm.o
 obj-$(CONFIG_XEN_PV)		+= xen-asm_$(BITS).o
 
 obj-$(CONFIG_XEN_PVH)		+= enlighten_pvh.o
-obj-$(CONFIG_XEN_PVH)	 	+= xen-pvh.o
 
 obj-$(CONFIG_EVENT_TRACING)	+= trace.o
 
diff --git a/arch/x86/xen/enlighten_pvh.c b/arch/x86/xen/enlighten_pvh.c
index 02e3ab7ff242..35b7599d2d0b 100644
--- a/arch/x86/xen/enlighten_pvh.c
+++ b/arch/x86/xen/enlighten_pvh.c
@@ -6,103 +6,45 @@
 #include <asm/io_apic.h>
 #include <asm/hypervisor.h>
 #include <asm/e820/api.h>
-#include <asm/x86_init.h>
 
+#include <xen/xen.h>
 #include <asm/xen/interface.h>
 #include <asm/xen/hypercall.h>
 
-#include <xen/xen.h>
 #include <xen/interface/memory.h>
-#include <xen/interface/hvm/start_info.h>
 
 /*
  * PVH variables.
  *
- * xen_pvh pvh_bootparams and pvh_start_info need to live in data segment
- * since they are used after startup_{32|64}, which clear .bss, are invoked.
+ * The variable xen_pvh needs to live in the data segment since it is used
+ * after startup_{32|64} is invoked, which will clear the .bss segment.
  */
 bool xen_pvh __attribute__((section(".data"))) = 0;
-struct boot_params pvh_bootparams __attribute__((section(".data")));
-struct hvm_start_info pvh_start_info __attribute__((section(".data")));
-
-unsigned int pvh_start_info_sz = sizeof(pvh_start_info);
 
-static u64 pvh_get_root_pointer(void)
+void __init xen_pvh_init(void)
 {
-	return pvh_start_info.rsdp_paddr;
+	u32 msr;
+	u64 pfn;
+
+	xen_pvh = 1;
+	xen_start_flags = pvh_start_info.flags;
+
+	msr = cpuid_ebx(xen_cpuid_base() + 2);
+	pfn = __pa(hypercall_page);
+	wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
 }
 
-static void __init init_pvh_bootparams(void)
+void __init mem_map_via_hcall(struct boot_params *boot_params_p)
 {
 	struct xen_memory_map memmap;
 	int rc;
 
-	memset(&pvh_bootparams, 0, sizeof(pvh_bootparams));
-
-	memmap.nr_entries = ARRAY_SIZE(pvh_bootparams.e820_table);
-	set_xen_guest_handle(memmap.buffer, pvh_bootparams.e820_table);
+	memmap.nr_entries = ARRAY_SIZE(boot_params_p->e820_table);
+	set_xen_guest_handle(memmap.buffer, boot_params_p->e820_table);
 	rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
 	if (rc) {
 		xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);
 		BUG();
 	}
-	pvh_bootparams.e820_entries = memmap.nr_entries;
-
-	if (pvh_bootparams.e820_entries < E820_MAX_ENTRIES_ZEROPAGE - 1) {
-		pvh_bootparams.e820_table[pvh_bootparams.e820_entries].addr =
-			ISA_START_ADDRESS;
-		pvh_bootparams.e820_table[pvh_bootparams.e820_entries].size =
-			ISA_END_ADDRESS - ISA_START_ADDRESS;
-		pvh_bootparams.e820_table[pvh_bootparams.e820_entries].type =
-			E820_TYPE_RESERVED;
-		pvh_bootparams.e820_entries++;
-	} else
-		xen_raw_printk("Warning: Can fit ISA range into e820\n");
-
-	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 = (2 << 8) | 12;
-	pvh_bootparams.hdr.type_of_loader = (9 << 4) | 0; /* Xen loader */
-
-	x86_init.acpi.get_root_pointer = pvh_get_root_pointer;
-}
-
-/*
- * 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;
-	xen_start_flags = pvh_start_info.flags;
-
-	msr = cpuid_ebx(xen_cpuid_base() + 2);
-	pfn = __pa(hypercall_page);
-	wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
-
-	init_pvh_bootparams();
+	boot_params_p->e820_entries = memmap.nr_entries;
 }
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index bb1c2da0381d..1e9ef0ba30a5 100644
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -12,6 +12,7 @@
 #include <asm/segment.h>
 #include <asm/asm-offsets.h>
 #include <asm/thread_info.h>
+#include <asm/asm.h>
 
 #include <xen/interface/xen.h>
 
@@ -24,6 +25,7 @@ ENTRY(xen_\name)
 	pop %r11
 	jmp  \name
 END(xen_\name)
+_ASM_NOKPROBE(xen_\name)
 .endm
 
 xen_pv_trap divide_error
diff --git a/arch/x86/xen/xen-pvh.S b/arch/x86/xen/xen-pvh.S
deleted file mode 100644
index 1f8825bbaffb..000000000000
--- a/arch/x86/xen/xen-pvh.S
+++ /dev/null
@@ -1,177 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-
-/*
- * Copyright C 2016, Oracle and/or its affiliates. All rights reserved.
- */
-
-	.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.
- */
-
-#define PVH_GDT_ENTRY_CS	1
-#define PVH_GDT_ENTRY_DS	2
-#define PVH_GDT_ENTRY_CANARY	3
-#define PVH_CS_SEL		(PVH_GDT_ENTRY_CS * 8)
-#define PVH_DS_SEL		(PVH_GDT_ENTRY_DS * 8)
-#define PVH_CANARY_SEL		(PVH_GDT_ENTRY_CANARY * 8)
-
-ENTRY(pvh_start_xen)
-	cld
-
-	lgdt (_pa(gdt))
-
-	mov $PVH_DS_SEL,%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_top_pgt), %eax
-	mov %eax, %cr3
-	mov $(X86_CR0_PG | X86_CR0_PE), %eax
-	mov %eax, %cr0
-
-	/* Jump to 64-bit mode. */
-	ljmp $PVH_CS_SEL, $_pa(1f)
-
-	/* 64-bit entry point. */
-	.code64
-1:
-	/* Set base address in stack canary descriptor. */
-	mov $MSR_GS_BASE,%ecx
-	mov $_pa(canary), %eax
-	xor %edx, %edx
-	wrmsr
-
-	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 */
-
-	/* Set base address in stack canary descriptor. */
-	movl $_pa(gdt_start),%eax
-	movl $_pa(canary),%ecx
-	movw %cx, (PVH_GDT_ENTRY_CANARY * 8) + 2(%eax)
-	shrl $16, %ecx
-	movb %cl, (PVH_GDT_ENTRY_CANARY * 8) + 4(%eax)
-	movb %ch, (PVH_GDT_ENTRY_CANARY * 8) + 7(%eax)
-
-	mov $PVH_CANARY_SEL,%eax
-	mov %eax,%gs
-
-	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 $PVH_CS_SEL, $1f
-1:
-	call xen_prepare_pvh
-	mov $_pa(pvh_bootparams), %esi
-
-	/* startup_32 doesn't expect paging and PAE to be on. */
-	ljmp $PVH_CS_SEL, $_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 $PVH_CS_SEL, $_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 */
-#ifdef CONFIG_X86_64
-	.quad GDT_ENTRY(0xa09a, 0, 0xfffff) /* PVH_CS_SEL */
-#else
-	.quad GDT_ENTRY(0xc09a, 0, 0xfffff) /* PVH_CS_SEL */
-#endif
-	.quad GDT_ENTRY(0xc092, 0, 0xfffff) /* PVH_DS_SEL */
-	.quad GDT_ENTRY(0x4090, 0, 0x18)    /* PVH_CANARY_SEL */
-gdt_end:
-
-	.balign 16
-canary:
-	.fill 48, 1, 0
-
-early_stack:
-	.fill BOOT_STACK_SIZE, 1, 0
-early_stack_end:
-
-	ELFNOTE(Xen, XEN_ELFNOTE_PHYS32_ENTRY,
-	             _ASM_PTR (pvh_start_xen - __START_KERNEL_map))