From cd602a37e80c791adf2a256d2aedec60b898cd51 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 30 Jun 2016 18:40:47 +0100 Subject: arm: KVM: Simplify HYP init Just like for arm64, we can now make the HYP setup a lot simpler, and we can now initialise it in one go (instead of the two phases we currently have). Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 15 +++++-------- arch/arm/kvm/init.S | 49 ++++++++--------------------------------- 2 files changed, 14 insertions(+), 50 deletions(-) diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 020f4eb14f0b..eafbfd5ad34a 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -250,18 +250,13 @@ static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr, * code. The init code doesn't need to preserve these * registers as r0-r3 are already callee saved according to * the AAPCS. - * Note that we slightly misuse the prototype by casing the + * Note that we slightly misuse the prototype by casting the * stack pointer to a void *. - * - * We don't have enough registers to perform the full init in - * one go. Install the boot PGD first, and then install the - * runtime PGD, stack pointer and vectors. The PGDs are always - * passed as the third argument, in order to be passed into - * r2-r3 to the init code (yes, this is compliant with the - * PCS!). - */ - kvm_call_hyp(NULL, 0, boot_pgd_ptr); + * The PGDs are always passed as the third argument, in order + * to be passed into r2-r3 to the init code (yes, this is + * compliant with the PCS!). + */ kvm_call_hyp((void*)hyp_stack_ptr, vector_ptr, pgd_ptr); } diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S index 1f9ae17476f9..b82a99dcfb61 100644 --- a/arch/arm/kvm/init.S +++ b/arch/arm/kvm/init.S @@ -32,23 +32,13 @@ * r2,r3 = Hypervisor pgd pointer * * The init scenario is: - * - We jump in HYP with four parameters: boot HYP pgd, runtime HYP pgd, - * runtime stack, runtime vectors - * - Enable the MMU with the boot pgd - * - Jump to a target into the trampoline page (remember, this is the same - * physical page!) - * - Now switch to the runtime pgd (same VA, and still the same physical - * page!) + * - We jump in HYP with 3 parameters: runtime HYP pgd, runtime stack, + * runtime vectors * - Invalidate TLBs * - Set stack and vectors + * - Setup the page tables + * - Enable the MMU * - Profit! (or eret, if you only care about the code). - * - * As we only have four registers available to pass parameters (and we - * need six), we split the init in two phases: - * - Phase 1: r0 = 0, r1 = 0, r2,r3 contain the boot PGD. - * Provides the basic HYP init, and enable the MMU. - * - Phase 2: r0 = ToS, r1 = vectors, r2,r3 contain the runtime PGD. - * Switches to the runtime PGD, set stack and vectors. */ .text @@ -68,8 +58,11 @@ __kvm_hyp_init: W(b) . __do_hyp_init: - cmp r0, #0 @ We have a SP? - bne phase2 @ Yes, second stage init + @ Set stack pointer + mov sp, r0 + + @ Set HVBAR to point to the HYP vectors + mcr p15, 4, r1, c12, c0, 0 @ HVBAR @ Set the HTTBR to point to the hypervisor PGD pointer passed mcrr p15, 4, rr_lo_hi(r2, r3), c2 @@ -114,33 +107,9 @@ __do_hyp_init: THUMB( ldr r2, =(HSCTLR_M | HSCTLR_A | HSCTLR_TE) ) orr r1, r1, r2 orr r0, r0, r1 - isb mcr p15, 4, r0, c1, c0, 0 @ HSCR - - @ End of init phase-1 - eret - -phase2: - @ Set stack pointer - mov sp, r0 - - @ Set HVBAR to point to the HYP vectors - mcr p15, 4, r1, c12, c0, 0 @ HVBAR - - @ Jump to the trampoline page - ldr r0, =TRAMPOLINE_VA - adr r1, target - bfi r0, r1, #0, #PAGE_SHIFT - ret r0 - -target: @ We're now in the trampoline code, switch page tables - mcrr p15, 4, rr_lo_hi(r2, r3), c2 isb - @ Invalidate the old TLBs - mcr p15, 4, r0, c8, c7, 0 @ TLBIALLH - dsb ish - eret .ltorg -- cgit