Commit 50cc02e5 authored Dec 27, 2019 by Frederic Weisbecker Committed by Ingo Molnar Jan 07, 2020

x86/context-tracking: Remove exception_enter/exit() from...


x86/context-tracking: Remove exception_enter/exit() from KVM_PV_REASON_PAGE_NOT_PRESENT async page fault

This is a leftover. Page faults, just like most other exceptions,
are protected inside user_exit() / user_enter() calls in x86 entry code
when we fault from userspace. So this pair of calls is now superfluous.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Link: https://lkml.kernel.org/r/20191227163612.10039-3-frederic@kernel.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent ee6352b2

arch/x86/kernel/kvm.c

+0 −4

Original line number	Diff line number	Diff line
		@@ -245,17 +245,13 @@ NOKPROBE_SYMBOL(kvm_read_and_reset_pf_reason);
		dotraplinkage void
		do_async_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address)
		{
		enum ctx_state prev_state;

		switch (kvm_read_and_reset_pf_reason()) {
		default:
		do_page_fault(regs, error_code, address);
		break;
		case KVM_PV_REASON_PAGE_NOT_PRESENT:
		/* page is swapped out by the host. */
		prev_state = exception_enter();
		kvm_async_pf_task_wait((u32)address, !user_mode(regs));
		exception_exit(prev_state);
		break;
		case KVM_PV_REASON_PAGE_READY:
		rcu_irq_enter();

Admin message