diff options
| author | James Morse <james.morse@arm.com> | 2018-01-08 15:38:03 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2018-01-13 10:44:04 +0000 |
| commit | 32b03d1059667a39e089c45ee38ec9c16332430f (patch) | |
| tree | 6cbdacd0a895bae32074a0e0a14f566d213edfdd /arch/arm64/kvm/hyp/entry.S | |
| parent | 3423cab3e05fe41d42d8905bb2b01d601a03626f (diff) | |
KVM: arm64: Store vcpu on the stack during __guest_enter()
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>
Diffstat (limited to 'arch/arm64/kvm/hyp/entry.S')
| -rw-r--r-- | arch/arm64/kvm/hyp/entry.S | 10 |
1 files changed, 7 insertions, 3 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 |