summaryrefslogtreecommitdiffstats
path: root/arch/arm64/kvm/hyp/entry.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm64/kvm/hyp/entry.S')
-rw-r--r--arch/arm64/kvm/hyp/entry.S36
1 files changed, 29 insertions, 7 deletions
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S
index bd34016354ba..e5cc8d66bf53 100644
--- a/arch/arm64/kvm/hyp/entry.S
+++ b/arch/arm64/kvm/hyp/entry.S
@@ -6,6 +6,7 @@
#include <linux/linkage.h>
+#include <asm/alternative.h>
#include <asm/asm-offsets.h>
#include <asm/assembler.h>
#include <asm/fpsimdmacros.h>
@@ -52,6 +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:
@@ -127,8 +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
@@ -136,8 +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
@@ -145,10 +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
@@ -161,6 +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.