On Thu, Jan 17, 2013 at 11:37 AM, Marc Zyngier <marc.zyng...@arm.com> wrote: > On 16/01/13 17:59, Christoffer Dall wrote: >> When the guest accesses I/O memory this will create data abort >> exceptions and they are handled by decoding the HSR information >> (physical address, read/write, length, register) and forwarding reads >> and writes to QEMU which performs the device emulation. >> >> Certain classes of load/store operations do not support the syndrome >> information provided in the HSR. We don't support decoding these (patches >> are available elsewhere), so we report an error to user space in this case. >> >> This requires changing the general flow somewhat since new calls to run >> the VCPU must check if there's a pending MMIO load and perform the write >> after userspace has made the data available. >> >> Reviewed-by: Will Deacon <will.dea...@arm.com> >> Reviewed-by: Marcelo Tosatti <mtosa...@redhat.com> >> Signed-off-by: Rusty Russell <ru...@rustcorp.com.au> >> Signed-off-by: Marc Zyngier <marc.zyng...@arm.com> >> Signed-off-by: Christoffer Dall <c.d...@virtualopensystems.com> > > [...] > >> diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S >> index 04a9705..702743e 100644 >> --- a/arch/arm/kvm/interrupts.S >> +++ b/arch/arm/kvm/interrupts.S >> @@ -192,6 +192,44 @@ after_vfp_restore: >> mov r0, r1 @ Return the return code >> bx lr @ return to IOCTL >> >> + >> +/******************************************************************** >> + * Translate VA to PA >> + * >> + * u64 __kvm_va_to_pa(struct kvm_vcpu *vcpu, u32 va, bool priv) >> + * >> + * Arguments: >> + * r0: pointer to vcpu struct >> + * r1: virtual address to map (rounded to page) >> + * r2: 1 = P1 (read) mapping, 0 = P0 (read) mapping. >> + * Returns 64 bit PAR value. >> + */ >> +ENTRY(__kvm_va_to_pa) >> + push {r4-r12} >> + >> + @ Fold flag into r1, easier than using stack. >> + cmp r2, #0 >> + movne r2, #1 >> + orr r1, r1, r2 >> + >> + @ This swaps too many registers, but we're in the slow path anyway. >> + read_cp15_state store_to_vcpu = 0 >> + write_cp15_state read_from_vcpu = 1 >> + >> + ands r2, r1, #1 >> + bic r1, r1, r2 >> + mcrne p15, 0, r1, c7, c8, 0 @ VA to PA, ATS1CPR >> + mcreq p15, 0, r1, c7, c8, 2 @ VA to PA, ATS1CUR >> + isb >> + >> + @ Restore host state. >> + read_cp15_state store_to_vcpu = 1 >> + write_cp15_state read_from_vcpu = 0 >> + >> + mrrc p15, 0, r0, r1, c7 @ PAR >> + pop {r4-r12} >> + bx lr >> + > > Do we still need this function? Now that the MMIO emulation is gone, > there should be no need to perform a manual translation. > > I can't even find a caller for it either. > I'm trying to leave bits and pieces of the emulation code in here in hope that it will spawn itself into a glorious unified solution that decodes everything and that everybody will be happy with :)
I'll remove it. Thanks. -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html