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| 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/hyp-entry.S | |
| parent | Merge branch 'for-next/perf' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux (diff) | |
| download | linux-dev-32b03d1059667a39e089c45ee38ec9c16332430f.tar.xz linux-dev-32b03d1059667a39e089c45ee38ec9c16332430f.zip | |
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/hyp-entry.S')
| -rw-r--r-- | arch/arm64/kvm/hyp/hyp-entry.S | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index 5170ce1021da..fce7cc507e0a 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -104,6 +104,7 @@ 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 @@ -116,19 +117,18 @@ 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 |