diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/entry.S')
| -rw-r--r-- | arch/arm64/kvm/hyp/entry.S | 49 |
1 files changed, 30 insertions, 19 deletions
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index 93ba3d7ef027..e5cc8d66bf53 100644 --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -1,22 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * Copyright (C) 2015 - ARM Ltd * Author: Marc Zyngier <marc.zyngier@arm.com> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * 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/>. */ #include <linux/linkage.h> +#include <asm/alternative.h> #include <asm/asm-offsets.h> #include <asm/assembler.h> #include <asm/fpsimdmacros.h> @@ -63,6 +53,20 @@ ENTRY(__guest_enter) // Store the host regs save_callee_saved_regs x1 + // Now the host state is stored if we have a pending RAS SError it must + // affect the host. If any asynchronous exception is pending we defer + // the guest entry. The DSB isn't necessary before v8.2 as any SError + // would be fatal. +alternative_if ARM64_HAS_RAS_EXTN + dsb nshst + isb +alternative_else_nop_endif + mrs x1, isr_el1 + cbz x1, 1f + mov x0, #ARM_EXCEPTION_IRQ + ret + +1: add x18, x0, #VCPU_CONTEXT // Macro ptrauth_switch_to_guest format: @@ -138,8 +142,8 @@ ENTRY(__guest_exit) alternative_if ARM64_HAS_RAS_EXTN // If we have the RAS extensions we can consume a pending error - // without an unmask-SError and isb. - esb + // without an unmask-SError and isb. The ESB-instruction consumed any + // pending guest error when we took the exception from the guest. mrs_s x2, SYS_DISR_EL1 str x2, [x1, #(VCPU_FAULT_DISR - VCPU_CONTEXT)] cbz x2, 1f @@ -147,8 +151,16 @@ alternative_if ARM64_HAS_RAS_EXTN orr x0, x0, #(1<<ARM_EXIT_WITH_SERROR_BIT) 1: ret alternative_else - // If we have a pending asynchronous abort, now is the - // time to find out. From your VAXorcist book, page 666: + dsb sy // Synchronize against in-flight ld/st + isb // Prevent an early read of side-effect free ISR + mrs x2, isr_el1 + tbnz x2, #8, 2f // ISR_EL1.A + ret + nop +2: +alternative_endif + // We know we have a pending asynchronous abort, now is the + // time to flush it out. From your VAXorcist book, page 666: // "Threaten me not, oh Evil one! For I speak with // the power of DEC, and I command thee to show thyself!" mrs x2, elr_el2 @@ -156,10 +168,7 @@ alternative_else mrs x4, spsr_el2 mov x5, x0 - dsb sy // Synchronize against in-flight ld/st - nop msr daifclr, #4 // Unmask aborts -alternative_endif // This is our single instruction exception window. A pending // SError is guaranteed to occur at the earliest when we unmask @@ -172,6 +181,8 @@ abort_guest_exit_start: .global abort_guest_exit_end abort_guest_exit_end: + msr daifset, #4 // Mask aborts + // If the exception took place, restore the EL1 exception // context so that we can report some information. // Merge the exception code with the SError pending bit. |