diff options
author | James Morse <james.morse@arm.com> | 2018-07-20 10:56:13 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-22 14:27:40 +0200 |
commit | 02891fdbfd1e61feec902b640d9eb415f04de693 (patch) | |
tree | 9e9e623c7c820621ee1069f7ec8e76c4adeb982f | |
parent | c488ae439ded49d20fcd264dec39f30300bbd2c1 (diff) |
KVM: arm64: Store vcpu on the stack during __guest_enter()
Commit 32b03d1059667a39e089c45ee38ec9c16332430f upstream.
KVM uses tpidr_el2 as its private vcpu register, which makes sense for
non-vhe world switch as only KVM can access this register. This means
vhe Linux has to use tpidr_el1, which KVM has to save/restore as part
of the host context.
If the SDEI handler code runs behind KVMs back, it mustn't access any
per-cpu variables. To allow this on systems with vhe we need to make
the host use tpidr_el2, saving KVM from save/restoring it.
__guest_enter() stores the host_ctxt on the stack, do the same with
the vcpu.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | arch/arm64/kvm/hyp/entry.S | 10 | ||||
-rw-r--r-- | arch/arm64/kvm/hyp/hyp-entry.S | 6 |
2 files changed, 10 insertions, 6 deletions
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index 12ee62d6d410..9a8ab5dddd9e 100644 --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -62,8 +62,8 @@ ENTRY(__guest_enter) // Store the host regs save_callee_saved_regs x1 - // Store the host_ctxt for use at exit time - str x1, [sp, #-16]! + // Store host_ctxt and vcpu for use at exit time + stp x1, x0, [sp, #-16]! add x18, x0, #VCPU_CONTEXT @@ -159,6 +159,10 @@ abort_guest_exit_end: ENDPROC(__guest_exit) ENTRY(__fpsimd_guest_restore) + // x0: esr + // x1: vcpu + // x2-x29,lr: vcpu regs + // vcpu x0-x1 on the stack stp x2, x3, [sp, #-16]! stp x4, lr, [sp, #-16]! @@ -173,7 +177,7 @@ alternative_else alternative_endif isb - mrs x3, tpidr_el2 + mov x3, x1 ldr x0, [x3, #VCPU_HOST_CONTEXT] kern_hyp_va x0 diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index 4e9d50c3e658..acd75c905084 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -121,24 +121,24 @@ el1_trap: /* * x0: ESR_EC */ + ldr x1, [sp, #16 + 8] // vcpu stored by __guest_enter /* Guest accessed VFP/SIMD registers, save host, restore Guest */ cmp x0, #ESR_ELx_EC_FP_ASIMD b.eq __fpsimd_guest_restore - mrs x1, tpidr_el2 mov x0, #ARM_EXCEPTION_TRAP b __guest_exit el1_irq: stp x0, x1, [sp, #-16]! - mrs x1, tpidr_el2 + ldr x1, [sp, #16 + 8] mov x0, #ARM_EXCEPTION_IRQ b __guest_exit el1_error: stp x0, x1, [sp, #-16]! - mrs x1, tpidr_el2 + ldr x1, [sp, #16 + 8] mov x0, #ARM_EXCEPTION_EL1_SERROR b __guest_exit |