Commit 555b6841 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86_mm_for_6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 mm updates from Dave Hansen:

 - Add a warning when memory encryption conversions fail. These
   operations require VMM cooperation, even in CoCo environments where
   the VMM is untrusted. While it's _possible_ that memory pressure
   could trigger the new warning, the odds are that a guest would only
   see this from an attacking VMM.

 - Simplify page fault code by re-enabling interrupts unconditionally

 - Avoid truncation issues when pfns are passed in to pfn_to_kaddr()
   with small (<64-bit) types.

* tag 'x86_mm_for_6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/cpa: Warn for set_memory_XXcrypted() VMM fails
  x86/mm: Get rid of conditional IF flag handling in page fault path
  x86/mm: Ensure input to pfn_to_kaddr() is treated as a 64-bit type
parents 685d9821 82ace185

arch/x86/include/asm/page.h

+5 −1
Original line number Diff line number Diff line
@@ -66,10 +66,14 @@ static inline void copy_user_page(void *to, void *from, unsigned long vaddr, 
 * virt_addr_valid(kaddr) returns true.

 */

#define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)

#define pfn_to_kaddr(pfn)      __va((pfn) << PAGE_SHIFT)

extern bool __virt_addr_valid(unsigned long kaddr);

#define virt_addr_valid(kaddr)	__virt_addr_valid((unsigned long) (kaddr))



static __always_inline void *pfn_to_kaddr(unsigned long pfn)

{

	return __va(pfn << PAGE_SHIFT);

}



static __always_inline u64 __canonical_address(u64 vaddr, u8 vaddr_bits)

{

	return ((s64)vaddr << (64 - vaddr_bits)) >> (64 - vaddr_bits);

arch/x86/mm/fault.c

+14 −13
Original line number Diff line number Diff line
@@ -1299,21 +1299,14 @@ void do_user_addr_fault(struct pt_regs *regs, 
		return;

	}



	/*

	 * It's safe to allow irq's after cr2 has been saved and the

	 * vmalloc fault has been handled.

	 *

	 * User-mode registers count as a user access even for any

	 * potential system fault or CPU buglet:

	 */

	if (user_mode(regs)) {

		local_irq_enable();

		flags |= FAULT_FLAG_USER;

	} else {

		if (regs->flags & X86_EFLAGS_IF)

			local_irq_enable();

	/* Legacy check - remove this after verifying that it doesn't trigger */

	if (WARN_ON_ONCE(!(regs->flags & X86_EFLAGS_IF))) {

		bad_area_nosemaphore(regs, error_code, address);

		return;

	}



	local_irq_enable();



	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);



	/*
@@ -1329,6 +1322,14 @@ void do_user_addr_fault(struct pt_regs *regs, 
	if (error_code & X86_PF_INSTR)

		flags |= FAULT_FLAG_INSTRUCTION;



	/*

	 * We set FAULT_FLAG_USER based on the register state, not

	 * based on X86_PF_USER. User space accesses that cause

	 * system page faults are still user accesses.

	 */

	if (user_mode(regs))

		flags |= FAULT_FLAG_USER;



#ifdef CONFIG_X86_64

	/*

	 * Faults in the vsyscall page might need emulation.  The

arch/x86/mm/pat/set_memory.c

+13 −6
Original line number Diff line number Diff line
@@ -2157,7 +2157,7 @@ static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc) 


	/* Notify hypervisor that we are about to set/clr encryption attribute. */

	if (!x86_platform.guest.enc_status_change_prepare(addr, numpages, enc))

		return -EIO;

		goto vmm_fail;



	ret = __change_page_attr_set_clr(&cpa, 1);
@@ -2170,13 +2170,20 @@ static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc) 
	 */

	cpa_flush(&cpa, 0);



	if (ret)

		return ret;



	/* Notify hypervisor that we have successfully set/clr encryption attribute. */

	if (!ret) {

	if (!x86_platform.guest.enc_status_change_finish(addr, numpages, enc))

			ret = -EIO;

	}

		goto vmm_fail;



	return ret;

	return 0;



vmm_fail:

	WARN_ONCE(1, "CPA VMM failure to convert memory (addr=%p, numpages=%d) to %s.\n",

		  (void *)addr, numpages, enc ? "private" : "shared");



	return -EIO;

}



static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)