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authorMarc Zyngier <marc.zyngier@arm.com>2017-04-03 19:37:44 +0100
committerChristoffer Dall <cdall@linaro.org>2017-04-09 07:49:23 -0700
commit506c372ac41dc0c7c1f50f718a8a53cb0748ea96 (patch)
tree768216dce16659e5c92afb8c107e59ea3517a295 /arch/arm64/kvm
parent4adb1341c7ef68af54732ef11f69faedffa6acb7 (diff)
arm64: KVM: Implement HVC_SOFT_RESTART in the init code
Another missing stub hypercall is HVC_SOFT_RESTART. It turns out that it is pretty easy to implement in terms of HVC_RESET_VECTORS (since it needs to turn the MMU off). Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
Diffstat (limited to 'arch/arm64/kvm')
-rw-r--r--arch/arm64/kvm/hyp-init.S31
1 files changed, 23 insertions, 8 deletions
diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
index b7a8f12293cc..0ad34fd6d2fc 100644
--- a/arch/arm64/kvm/hyp-init.S
+++ b/arch/arm64/kvm/hyp-init.S
@@ -129,21 +129,36 @@ ENTRY(__kvm_handle_stub_hvc)
mrs x0, vbar_el2
b exit
+1: cmp x0, #HVC_SOFT_RESTART
+ b.ne 1f
+
+ /* This is where we're about to jump, staying at EL2 */
+ msr elr_el2, x1
+ mov x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT | PSR_MODE_EL2h)
+ msr spsr_el2, x0
+
+ /* Shuffle the arguments, and don't come back */
+ mov x0, x2
+ mov x1, x3
+ mov x2, x4
+ b reset
+
1: cmp x0, #HVC_RESET_VECTORS
b.ne 1f
+reset:
/*
- * Reset kvm back to the hyp stub.
+ * Reset kvm back to the hyp stub. Do not clobber x0-x4 in
+ * case we coming via HVC_SOFT_RESTART.
*/
- /* We're now in idmap, disable MMU */
- mrs x0, sctlr_el2
- ldr x1, =SCTLR_ELx_FLAGS
- bic x0, x0, x1 // Clear SCTL_M and etc
- msr sctlr_el2, x0
+ mrs x5, sctlr_el2
+ ldr x6, =SCTLR_ELx_FLAGS
+ bic x5, x5, x6 // Clear SCTL_M and etc
+ msr sctlr_el2, x5
isb
/* Install stub vectors */
- adr_l x0, __hyp_stub_vectors
- msr vbar_el2, x0
+ adr_l x5, __hyp_stub_vectors
+ msr vbar_el2, x5
b exit
1: /* Bad stub call */