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/*
* Copyright (C) 2015 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/irqflags.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
#include <asm/tlbflush.h>
static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm,
unsigned long *flags)
{
u64 val;
local_irq_save(*flags);
/*
* With VHE enabled, we have HCR_EL2.{E2H,TGE} = {1,1}, and
* most TLB operations target EL2/EL0. In order to affect the
* guest TLBs (EL1/EL0), we need to change one of these two
* bits. Changing E2H is impossible (goodbye TTBR1_EL2), so
* let's flip TGE before executing the TLB operation.
*/
write_sysreg(kvm->arch.vttbr, vttbr_el2);
val = read_sysreg(hcr_el2);
val &= ~HCR_TGE;
write_sysreg(val, hcr_el2);
isb();
}
static void __hyp_text __tlb_switch_to_guest_nvhe(struct kvm *kvm,
unsigned long *flags)
{
write_sysreg(kvm->arch.vttbr, vttbr_el2);
isb();
}
static hyp_alternate_select(__tlb_switch_to_guest,
__tlb_switch_to_guest_nvhe,
__tlb_switch_to_guest_vhe,
ARM64_HAS_VIRT_HOST_EXTN);
static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm,
unsigned long flags)
{
/*
* We're done with the TLB operation, let's restore the host's
* view of HCR_EL2.
*/
write_sysreg(0, vttbr_el2);
write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
isb();
local_irq_restore(flags);
}
static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm,
unsigned long flags)
{
write_sysreg(0, vttbr_el2);
}
static hyp_alternate_select(__tlb_switch_to_host,
__tlb_switch_to_host_nvhe,
__tlb_switch_to_host_vhe,
ARM64_HAS_VIRT_HOST_EXTN);
void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
{
unsigned long flags;
dsb(ishst);
/* Switch to requested VMID */
kvm = kern_hyp_va(kvm);
__tlb_switch_to_guest()(kvm, &flags);
/*
* We could do so much better if we had the VA as well.
* Instead, we invalidate Stage-2 for this IPA, and the
* whole of Stage-1. Weep...
*/
ipa >>= 12;
__tlbi(ipas2e1is, ipa);
/*
* We have to ensure completion of the invalidation at Stage-2,
* since a table walk on another CPU could refill a TLB with a
* complete (S1 + S2) walk based on the old Stage-2 mapping if
* the Stage-1 invalidation happened first.
*/
dsb(ish);
__tlbi(vmalle1is);
dsb(ish);
isb();
/*
* If the host is running at EL1 and we have a VPIPT I-cache,
* then we must perform I-cache maintenance at EL2 in order for
* it to have an effect on the guest. Since the guest cannot hit
* I-cache lines allocated with a different VMID, we don't need
* to worry about junk out of guest reset (we nuke the I-cache on
* VMID rollover), but we do need to be careful when remapping
* executable pages for the same guest. This can happen when KSM
* takes a CoW fault on an executable page, copies the page into
* a page that was previously mapped in the guest and then needs
* to invalidate the guest view of the I-cache for that page
* from EL1. To solve this, we invalidate the entire I-cache when
* unmapping a page from a guest if we have a VPIPT I-cache but
* the host is running at EL1. As above, we could do better if
* we had the VA.
*
* The moral of this story is: if you have a VPIPT I-cache, then
* you should be running with VHE enabled.
*/
if (!has_vhe() && icache_is_vpipt())
__flush_icache_all();
__tlb_switch_to_host()(kvm, flags);
}
void __hyp_text __kvm_tlb_flush_vmid(struct kvm *kvm)
{
unsigned long flags;
dsb(ishst);
/* Switch to requested VMID */
kvm = kern_hyp_va(kvm);
__tlb_switch_to_guest()(kvm, &flags);
__tlbi(vmalls12e1is);
dsb(ish);
isb();
__tlb_switch_to_host()(kvm, flags);
}
void __hyp_text __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = kern_hyp_va(kern_hyp_va(vcpu)->kvm);
unsigned long flags;
/* Switch to requested VMID */
__tlb_switch_to_guest()(kvm, &flags);
__tlbi(vmalle1);
dsb(nsh);
isb();
__tlb_switch_to_host()(kvm, flags);
}
void __hyp_text __kvm_flush_vm_context(void)
{
dsb(ishst);
__tlbi(alle1is);
asm volatile("ic ialluis" : : );
dsb(ish);
}
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