Commit 158f238a authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-linus-6.13-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip 

Pull xen updates from Juergen Gross:

 - a series for booting as a PVH guest, doing some cleanups after the
   previous work to make PVH boot code position independent

 - a fix of the xenbus driver avoiding a leak in an error case

* tag 'for-linus-6.13-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: Fix the issue of resource not being properly released in xenbus_dev_probe()
  x86/pvh: Avoid absolute symbol references in .head.text
  x86/xen: Avoid relocatable quantities in Xen ELF notes
  x86/pvh: Omit needless clearing of phys_base
  x86/pvh: Use correct size value in GDT descriptor
  x86/pvh: Call C code via the kernel virtual mapping
parents ba1f9c8f afc545da

arch/x86/kernel/vmlinux.lds.S

+19 −0
Original line number Diff line number Diff line
@@ -531,3 +531,22 @@ INIT_PER_CPU(irq_stack_backing_store); 
#endif



#endif /* CONFIG_X86_64 */



/*

 * The symbols below are referenced using relative relocations in the

 * respective ELF notes. This produces build time constants that the

 * linker will never mark as relocatable. (Using just ABSOLUTE() is not

 * sufficient for that).

 */

#ifdef CONFIG_XEN

#ifdef CONFIG_XEN_PV

xen_elfnote_entry_value =

	ABSOLUTE(xen_elfnote_entry) + ABSOLUTE(startup_xen);

#endif

xen_elfnote_hypercall_page_value =

	ABSOLUTE(xen_elfnote_hypercall_page) + ABSOLUTE(hypercall_page);

#endif

#ifdef CONFIG_PVH

xen_elfnote_phys32_entry_value =

	ABSOLUTE(xen_elfnote_phys32_entry) + ABSOLUTE(pvh_start_xen - LOAD_OFFSET);

#endif

arch/x86/platform/pvh/head.S

+28 −22
Original line number Diff line number Diff line
@@ -6,7 +6,9 @@ 


	.code32

	.text

#ifdef CONFIG_X86_32

#define _pa(x)          ((x) - __START_KERNEL_map)

#endif

#define rva(x)          ((x) - pvh_start_xen)



#include <linux/elfnote.h>
@@ -52,7 +54,7 @@ 
#define PVH_CS_SEL		(PVH_GDT_ENTRY_CS * 8)

#define PVH_DS_SEL		(PVH_GDT_ENTRY_DS * 8)



SYM_CODE_START_LOCAL(pvh_start_xen)

SYM_CODE_START(pvh_start_xen)

	UNWIND_HINT_END_OF_STACK

	cld
@@ -72,8 +74,7 @@ SYM_CODE_START_LOCAL(pvh_start_xen) 
	movl $0, %esp



	leal rva(gdt)(%ebp), %eax

	leal rva(gdt_start)(%ebp), %ecx

	movl %ecx, 2(%eax)

	addl %eax, 2(%eax)

	lgdt (%eax)



	mov $PVH_DS_SEL,%eax
@@ -103,10 +104,23 @@ SYM_CODE_START_LOCAL(pvh_start_xen) 
	btsl $_EFER_LME, %eax

	wrmsr



	/*

	 * Reuse the non-relocatable symbol emitted for the ELF note to

	 * subtract the build time physical address of pvh_start_xen() from

	 * its actual runtime address, without relying on absolute 32-bit ELF

	 * relocations, as these are not supported by the linker when running

	 * in -pie mode, and should be avoided in .head.text in general.

	 */

	mov %ebp, %ebx

	subl $_pa(pvh_start_xen), %ebx /* offset */

	subl rva(xen_elfnote_phys32_entry)(%ebp), %ebx

	jz .Lpagetable_done



	/*

	 * Store the resulting load offset in phys_base.  __pa() needs

	 * phys_base set to calculate the hypercall page in xen_pvh_init().

	 */

	movl %ebx, rva(phys_base)(%ebp)



	/* Fixup page-tables for relocation. */

	leal rva(pvh_init_top_pgt)(%ebp), %edi

	movl $PTRS_PER_PGD, %ecx
@@ -165,20 +179,12 @@ SYM_CODE_START_LOCAL(pvh_start_xen) 
	xor %edx, %edx

	wrmsr



	/*

	 * Calculate load offset and store in phys_base.  __pa() needs

	 * phys_base set to calculate the hypercall page in xen_pvh_init().

	 */

	movq %rbp, %rbx

	subq $_pa(pvh_start_xen), %rbx

	movq %rbx, phys_base(%rip)

	call xen_prepare_pvh

	/*

	 * Clear phys_base.  __startup_64 will *add* to its value,

	 * so reset to 0.

	 */

	xor  %rbx, %rbx

	movq %rbx, phys_base(%rip)

	/* Call xen_prepare_pvh() via the kernel virtual mapping */

	leaq xen_prepare_pvh(%rip), %rax

	subq phys_base(%rip), %rax

	addq $__START_KERNEL_map, %rax

	ANNOTATE_RETPOLINE_SAFE

	call *%rax



	/* startup_64 expects boot_params in %rsi. */

	lea pvh_bootparams(%rip), %rsi
@@ -217,8 +223,8 @@ SYM_CODE_END(pvh_start_xen) 
	.section ".init.data","aw"

	.balign 8

SYM_DATA_START_LOCAL(gdt)

	.word gdt_end - gdt_start

	.long _pa(gdt_start) /* x86-64 will overwrite if relocated. */

	.word gdt_end - gdt_start - 1

	.long gdt_start - gdt

	.word 0

SYM_DATA_END(gdt)

SYM_DATA_START_LOCAL(gdt_start)
@@ -300,5 +306,5 @@ SYM_DATA_END(pvh_level2_kernel_pgt) 
		     .long KERNEL_IMAGE_SIZE - 1)

#endif



	ELFNOTE(Xen, XEN_ELFNOTE_PHYS32_ENTRY,

	             _ASM_PTR (pvh_start_xen - __START_KERNEL_map))
 
	ELFNOTE(Xen, XEN_ELFNOTE_PHYS32_ENTRY, .global xen_elfnote_phys32_entry;

		xen_elfnote_phys32_entry: _ASM_PTR xen_elfnote_phys32_entry_value - .)

arch/x86/tools/relocs.c

+1 −0
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = { 
	[S_ABS] =

	"^(xen_irq_disable_direct_reloc$|"

	"xen_save_fl_direct_reloc$|"

	"xen_elfnote_.+_offset$|"

	"VDSO|"

	"__kcfi_typeid_|"

	"__crc_)",

arch/x86/xen/xen-head.S

+4 −2
Original line number Diff line number Diff line
@@ -94,7 +94,8 @@ SYM_CODE_END(xen_cpu_bringup_again) 
	ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __START_KERNEL_map)

	/* Map the p2m table to a 512GB-aligned user address. */

	ELFNOTE(Xen, XEN_ELFNOTE_INIT_P2M,       .quad (PUD_SIZE * PTRS_PER_PUD))

	ELFNOTE(Xen, XEN_ELFNOTE_ENTRY,          _ASM_PTR startup_xen)

	ELFNOTE(Xen, XEN_ELFNOTE_ENTRY,          .globl xen_elfnote_entry;

		xen_elfnote_entry: _ASM_PTR xen_elfnote_entry_value - .)

	ELFNOTE(Xen, XEN_ELFNOTE_FEATURES,       .ascii "!writable_page_tables")

	ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE,       .asciz "yes")

	ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
@@ -115,7 +116,8 @@ SYM_CODE_END(xen_cpu_bringup_again) 
#else

# define FEATURES_DOM0 0

#endif

	ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, _ASM_PTR hypercall_page)

	ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, .globl xen_elfnote_hypercall_page;

		xen_elfnote_hypercall_page: _ASM_PTR xen_elfnote_hypercall_page_value - .)

	ELFNOTE(Xen, XEN_ELFNOTE_SUPPORTED_FEATURES,

		.long FEATURES_PV | FEATURES_PVH | FEATURES_DOM0)

	ELFNOTE(Xen, XEN_ELFNOTE_LOADER,         .asciz "generic")

drivers/xen/xenbus/xenbus_probe.c

+7 −1
Original line number Diff line number Diff line
@@ -313,7 +313,7 @@ int xenbus_dev_probe(struct device *_dev) 
	if (err) {

		dev_warn(&dev->dev, "watch_otherend on %s failed.\n",

		       dev->nodename);

		return err;

		goto fail_remove;

	}



	dev->spurious_threshold = 1;
@@ -322,6 +322,12 @@ int xenbus_dev_probe(struct device *_dev) 
			 dev->nodename);



	return 0;

fail_remove:

	if (drv->remove) {

		down(&dev->reclaim_sem);

		drv->remove(dev);

		up(&dev->reclaim_sem);

	}

fail_put:

	module_put(drv->driver.owner);

fail: