shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-07 03:15:31 +09:00
Code Issues Packages Projects Releases Wiki Activity

UPSTREAM: KVM: arm64: Don't adjust PC on SError during SMC trap

Browse Source 
On SMC trap, the prefered return address is set to that of the SMC
instruction itself. It is thus wrong to try and roll it back when
an SError occurs while trapping on SMC. It is still necessary on
HVC though, as HVC doesn't cause a trap, and sets ELR to returning
*after* the HVC.

It also became apparent that there is no 16bit encoding for an AArch32
HVC instruction, meaning that the displacement is always 4 bytes,
no matter what the ISA is. Take this opportunity to simplify it.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
(cherry picked from commit c22588c996)
Signed-off-by: Will Deacon <willdeacon@google.com>
Change-Id: I136cf6808dcc53d57d8f5952717aaa0a5efe8ba1
Bug: 178098380
Test: atest VirtualizationHostTestCases on an EL2-enabled device
This commit is contained in:
Marc Zyngier
2020-10-13 11:56:50 +01:00
committed by Will Deacon
parent 19a12c6d1c
commit 569af95460
1 changed files with 8 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
arch/arm64/kvm/handle_exit.c
View File

@@ -245,15 +245,15 @@ int handle_exit(struct kvm_vcpu *vcpu, int exception_index)
u8 esr_ec = ESR_ELx_EC(kvm_vcpu_get_esr(vcpu));
/*
* HVC/SMC already have an adjusted PC, which we need
* to correct in order to return to after having
* injected the SError.
* HVC already have an adjusted PC, which we need to
* correct in order to return to after having injected
* the SError.
*
* SMC, on the other hand, is *trapped*, meaning its
* preferred return address is the SMC itself.
*/
if (esr_ec == ESR_ELx_EC_HVC32 || esr_ec == ESR_ELx_EC_HVC64 ||
esr_ec == ESR_ELx_EC_SMC32 || esr_ec == ESR_ELx_EC_SMC64) {
u32 adj = kvm_vcpu_trap_il_is32bit(vcpu) ? 4 : 2;
*vcpu_pc(vcpu) -= adj;
}
if (esr_ec == ESR_ELx_EC_HVC32 || esr_ec == ESR_ELx_EC_HVC64)
*vcpu_pc(vcpu) -= 4;
return 1;
}