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| author | James Morse <james.morse@arm.com> | 2018-07-20 12:52:51 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-22 15:28:50 +0300 |
| commit | ed812b882599c0ec27a9f58831fc6bfb4efdac80 (patch) | |
| tree | 6a983b1018f854700a9cb230f1ea8939747ab997 /arch/arm64/kvm | |
| parent | 115df2a7c5ba248360e4f92d78102c34f45977ee (diff) | |
| download | linux-ed812b882599c0ec27a9f58831fc6bfb4efdac80.tar.xz | |
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>
Diffstat (limited to 'arch/arm64/kvm')
| -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 9c45c6af1f58..fe4678f20a85 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 f49b53331d28..fc1613955090 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -120,6 +120,7 @@ el1_trap: /* * x0: ESR_EC */ + ldr x1, [sp, #16 + 8] // vcpu stored by __guest_enter /* * We trap the first access to the FP/SIMD to save the host context @@ -132,19 +133,18 @@ alternative_if_not ARM64_HAS_NO_FPSIMD b.eq __fpsimd_guest_restore alternative_else_nop_endif - 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 |