Release 4.14 arch/arm64/kvm/hyp/tlb.c

/*
 * 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 <asm/kvm_hyp.h>
#include <asm/tlbflush.h>



static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm)
{
	u64 val;

	/*
         * 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();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Marc Zyngier
49
100.00%
1
100.00%
Total
49
100.00%
1
100.00%



static void __hyp_text __tlb_switch_to_guest_nvhe(struct kvm *kvm)
{
	write_sysreg(kvm->arch.vttbr, vttbr_el2);
	isb();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Marc Zyngier
26
100.00%
1
100.00%
Total
26
100.00%
1
100.00%

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)
{
	/*
         * 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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Marc Zyngier
27
100.00%
1
100.00%
Total
27
100.00%
1
100.00%



static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm)
{
	write_sysreg(0, vttbr_el2);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Marc Zyngier
19
100.00%
1
100.00%
Total
19
100.00%
1
100.00%

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)
{
	dsb(ishst);

	/* Switch to requested VMID */
	kvm = kern_hyp_va(kvm);
	__tlb_switch_to_guest()(kvm);

	/*
         * 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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Marc Zyngier
57
68.67%
2
40.00%
Will Deacon
13
15.66%
1
20.00%
Christopher Covington
12
14.46%
1
20.00%
Christoffer Dall
1
1.20%
1
20.00%
Total
83
100.00%
5
100.00%



void __hyp_text __kvm_tlb_flush_vmid(struct kvm *kvm)
{
	dsb(ishst);

	/* Switch to requested VMID */
	kvm = kern_hyp_va(kvm);
	__tlb_switch_to_guest()(kvm);

	__tlbi(vmalls12e1is);
	dsb(ish);
	isb();

	__tlb_switch_to_host()(kvm);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Marc Zyngier
43
87.76%
2
50.00%
Christopher Covington
5
10.20%
1
25.00%
Christoffer Dall
1
2.04%
1
25.00%
Total
49
100.00%
4
100.00%



void __hyp_text __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu)
{
	struct kvm *kvm = kern_hyp_va(kern_hyp_va(vcpu)->kvm);

	/* Switch to requested VMID */
	__tlb_switch_to_guest()(kvm);

	__tlbi(vmalle1);
	dsb(nsh);
	isb();

	__tlb_switch_to_host()(kvm);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Marc Zyngier
47
90.38%
2
66.67%
Christopher Covington
5
9.62%
1
33.33%
Total
52
100.00%
3
100.00%



void __hyp_text __kvm_flush_vm_context(void)
{
	dsb(ishst);
	__tlbi(alle1is);
	asm volatile("ic ialluis" : : );
	dsb(ish);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Marc Zyngier
19
73.08%
1
33.33%
Christopher Covington
6
23.08%
1
33.33%
Christoffer Dall
1
3.85%
1
33.33%
Total
26
100.00%
3
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Marc Zyngier
315
87.02%
4
57.14%
Christopher Covington
31
8.56%
1
14.29%
Will Deacon
13
3.59%
1
14.29%
Christoffer Dall
3
0.83%
1
14.29%
Total
362
100.00%
7
100.00%
Directory: arch/arm64/kvm/hyp

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.