On Tue, Jun 07, 2016 at 11:58:32AM +0100, Marc Zyngier wrote: > 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 <marc.zyng...@arm.com> > --- > 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 020f4eb..eafbfd5 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 1f9ae17..b82a99d 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
probably just call this HYP pgd, HYP stack, and HYP vectors now > * - 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 how are we sure there are no stale entries in the TLB beyond the idmap region? Did we take care of this during kernel boot? What about hotplug/suspend stuff? Thanks, -Christoffer _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
