diff options
Diffstat (limited to 'arch/arm/kvm/init.S')
| -rw-r--r-- | arch/arm/kvm/init.S | 78 |
1 files changed, 59 insertions, 19 deletions
diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S index 9f37a79b880..f048338135f 100644 --- a/arch/arm/kvm/init.S +++ b/arch/arm/kvm/init.S @@ -21,13 +21,33 @@ #include <asm/asm-offsets.h> #include <asm/kvm_asm.h> #include <asm/kvm_arm.h> +#include <asm/kvm_mmu.h> /******************************************************************** * Hypervisor initialization * - should be called with: - * r0,r1 = Hypervisor pgd pointer - * r2 = top of Hyp stack (kernel VA) - * r3 = pointer to hyp vectors + * r0 = top of Hyp stack (kernel VA) + * r1 = pointer to hyp vectors + * 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!) + * - Invalidate TLBs + * - Set stack and vectors + * - 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 @@ -47,22 +67,25 @@ __kvm_hyp_init: W(b) . __do_hyp_init: + cmp r0, #0 @ We have a SP? + bne phase2 @ Yes, second stage init + @ Set the HTTBR to point to the hypervisor PGD pointer passed - mcrr p15, 4, r0, r1, c2 + mcrr p15, 4, r2, r3, c2 @ Set the HTCR and VTCR to the same shareability and cacheability @ settings as the non-secure TTBCR and with T0SZ == 0. mrc p15, 4, r0, c2, c0, 2 @ HTCR - ldr r12, =HTCR_MASK - bic r0, r0, r12 + ldr r2, =HTCR_MASK + bic r0, r0, r2 mrc p15, 0, r1, c2, c0, 2 @ TTBCR and r1, r1, #(HTCR_MASK & ~TTBCR_T0SZ) orr r0, r0, r1 mcr p15, 4, r0, c2, c0, 2 @ HTCR mrc p15, 4, r1, c2, c1, 2 @ VTCR - ldr r12, =VTCR_MASK - bic r1, r1, r12 + ldr r2, =VTCR_MASK + bic r1, r1, r2 bic r0, r0, #(~VTCR_HTCR_SH) @ clear non-reusable HTCR bits orr r1, r0, r1 orr r1, r1, #(KVM_VTCR_SL0 | KVM_VTCR_T0SZ | KVM_VTCR_S) @@ -85,24 +108,41 @@ __do_hyp_init: @ - Memory alignment checks: enabled @ - MMU: enabled (this code must be run from an identity mapping) mrc p15, 4, r0, c1, c0, 0 @ HSCR - ldr r12, =HSCTLR_MASK - bic r0, r0, r12 + ldr r2, =HSCTLR_MASK + bic r0, r0, r2 mrc p15, 0, r1, c1, c0, 0 @ SCTLR - ldr r12, =(HSCTLR_EE | HSCTLR_FI | HSCTLR_I | HSCTLR_C) - and r1, r1, r12 - ARM( ldr r12, =(HSCTLR_M | HSCTLR_A) ) - THUMB( ldr r12, =(HSCTLR_M | HSCTLR_A | HSCTLR_TE) ) - orr r1, r1, r12 + ldr r2, =(HSCTLR_EE | HSCTLR_FI | HSCTLR_I | HSCTLR_C) + and r1, r1, r2 + ARM( ldr r2, =(HSCTLR_M | HSCTLR_A) ) + 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 - isb - @ Set stack pointer and return to the kernel - mov sp, r2 + @ End of init phase-1 + eret + +phase2: + @ Set stack pointer + mov sp, r0 @ Set HVBAR to point to the HYP vectors - mcr p15, 4, r3, c12, c0, 0 @ HVBAR + 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 + mov pc, r0 + +target: @ We're now in the trampoline code, switch page tables + mcrr p15, 4, r2, r3, c2 + isb + + @ Invalidate the old TLBs + mcr p15, 4, r0, c8, c7, 0 @ TLBIALLH + dsb eret |