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| author | Marc Zyngier <marc.zyngier@arm.com> | 2017-04-03 21:37:53 +0300 |
|---|---|---|
| committer | Christoffer Dall <cdall@linaro.org> | 2017-04-09 17:49:28 +0300 |
| commit | bc845e4fbbbbe97bab3f1bcf688be0b5da420717 (patch) | |
| tree | 4e5c44a617dfdde8e7d71c02800172f6b36d38bf /arch/arm/kvm | |
| parent | 7d1bf4e05717d900e69b249b4f08f6b36b00fbf0 (diff) | |
| download | linux-bc845e4fbbbbe97bab3f1bcf688be0b5da420717.tar.xz | |
ARM: KVM: Implement HVC_RESET_VECTORS stub hypercall in the init code
In order to restore HYP mode to its original condition, KVM currently
implements __kvm_hyp_reset(). As we're moving towards a hyp-stub
defined API, it becomes necessary to implement HVC_RESET_VECTORS.
This patch adds the HVC_RESET_VECTORS hypercall to the KVM init
code, which so far lacked any form of hypercall support.
Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
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/arm/kvm')
| -rw-r--r-- | arch/arm/kvm/init.S | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S index bf89c919efc1..86a7008e75a3 100644 --- a/arch/arm/kvm/init.S +++ b/arch/arm/kvm/init.S @@ -23,6 +23,7 @@ #include <asm/kvm_asm.h> #include <asm/kvm_arm.h> #include <asm/kvm_mmu.h> +#include <asm/virt.h> /******************************************************************** * Hypervisor initialization @@ -39,6 +40,10 @@ * - Setup the page tables * - Enable the MMU * - Profit! (or eret, if you only care about the code). + * + * Another possibility is to get a HYP stub hypercall. + * We discriminate between the two by checking if r0 contains a value + * that is less than HVC_STUB_HCALL_NR. */ .text @@ -58,6 +63,10 @@ __kvm_hyp_init: W(b) . __do_hyp_init: + @ Check for a stub hypercall + cmp r0, #HVC_STUB_HCALL_NR + blo __kvm_handle_stub_hvc + @ Set stack pointer mov sp, r0 @@ -112,19 +121,31 @@ __do_hyp_init: eret - @ r0 : stub vectors address +ENTRY(__kvm_handle_stub_hvc) + cmp r0, #HVC_RESET_VECTORS + bne 1f ENTRY(__kvm_hyp_reset) /* We're now in idmap, disable MMU */ mrc p15, 4, r1, c1, c0, 0 @ HSCTLR - ldr r2, =(HSCTLR_M | HSCTLR_A | HSCTLR_C | HSCTLR_I) - bic r1, r1, r2 + ldr r0, =(HSCTLR_M | HSCTLR_A | HSCTLR_C | HSCTLR_I) + bic r1, r1, r0 mcr p15, 4, r1, c1, c0, 0 @ HSCTLR - /* Install stub vectors */ - mcr p15, 4, r0, c12, c0, 0 @ HVBAR - isb + /* + * Install stub vectors, using ardb's VA->PA trick. + */ +0: adr r0, 0b @ PA(0) + movw r1, #:lower16:__hyp_stub_vectors - 0b @ VA(stub) - VA(0) + movt r1, #:upper16:__hyp_stub_vectors - 0b + add r1, r1, r0 @ PA(stub) + mcr p15, 4, r1, c12, c0, 0 @ HVBAR + b exit + +1: ldr r0, =HVC_STUB_ERR +exit: eret +ENDPROC(__kvm_handle_stub_hvc) ENDPROC(__kvm_hyp_reset) .ltorg |