Commit fe5db27d authored by Ben Gardon's avatar Ben Gardon Committed by Paolo Bonzini
Browse files

kvm: x86/mmu: Init / Uninit the TDP MMU 

The TDP MMU offers an alternative mode of operation to the x86 shadow
paging based MMU, optimized for running an L1 guest with TDP. The TDP MMU
will require new fields that need to be initialized and torn down. Add
hooks into the existing KVM MMU initialization process to do that
initialization / cleanup. Currently the initialization and cleanup
fucntions do not do very much, however more operations will be added in
future patches.

Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.

This series can be viewed in Gerrit at:
	https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538



Signed-off-by: default avatarBen Gardon <bgardon@google.com>
Message-Id: <20201014182700.2888246-4-bgardon@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent c9180b72

arch/x86/include/asm/kvm_host.h

+9 −0
Original line number Diff line number Diff line
@@ -995,6 +995,15 @@ struct kvm_arch { 


	struct kvm_pmu_event_filter *pmu_event_filter;

	struct task_struct *nx_lpage_recovery_thread;



	/*

	 * Whether the TDP MMU is enabled for this VM. This contains a

	 * snapshot of the TDP MMU module parameter from when the VM was

	 * created and remains unchanged for the life of the VM. If this is

	 * true, TDP MMU handler functions will run for various MMU

	 * operations.

	 */

	bool tdp_mmu_enabled;

};



struct kvm_vm_stat {

arch/x86/kvm/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -16,7 +16,7 @@ kvm-$(CONFIG_KVM_ASYNC_PF) += $(KVM)/async_pf.o 
kvm-y			+= x86.o emulate.o i8259.o irq.o lapic.o \

			   i8254.o ioapic.o irq_comm.o cpuid.o pmu.o mtrr.o \

			   hyperv.o debugfs.o mmu/mmu.o mmu/page_track.o \

			   mmu/spte.o mmu/tdp_iter.o

			   mmu/spte.o mmu/tdp_iter.o mmu/tdp_mmu.o



kvm-intel-y		+= vmx/vmx.o vmx/vmenter.o vmx/pmu_intel.o vmx/vmcs12.o \

			   vmx/evmcs.o vmx/nested.o vmx/posted_intr.o

arch/x86/kvm/mmu/mmu.c

+5 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include "ioapic.h"

#include "mmu.h"

#include "mmu_internal.h"

#include "tdp_mmu.h"

#include "x86.h"

#include "kvm_cache_regs.h"

#include "kvm_emulate.h"
@@ -5377,6 +5378,8 @@ void kvm_mmu_init_vm(struct kvm *kvm) 
{

	struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker;



	kvm_mmu_init_tdp_mmu(kvm);



	node->track_write = kvm_mmu_pte_write;

	node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot;

	kvm_page_track_register_notifier(kvm, node);
@@ -5387,6 +5390,8 @@ void kvm_mmu_uninit_vm(struct kvm *kvm) 
	struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker;



	kvm_page_track_unregister_notifier(kvm, node);



	kvm_mmu_uninit_tdp_mmu(kvm);

}



void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)

arch/x86/kvm/mmu/tdp_mmu.c

0 → 100644
+30 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



#include "tdp_mmu.h"



static bool __read_mostly tdp_mmu_enabled = false;



static bool is_tdp_mmu_enabled(void)

{

#ifdef CONFIG_X86_64

	return tdp_enabled && READ_ONCE(tdp_mmu_enabled);

#else

	return false;

#endif /* CONFIG_X86_64 */

}



/* Initializes the TDP MMU for the VM, if enabled. */

void kvm_mmu_init_tdp_mmu(struct kvm *kvm)

{

	if (!is_tdp_mmu_enabled())

		return;



	/* This should not be changed for the lifetime of the VM. */

	kvm->arch.tdp_mmu_enabled = true;

}



void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm)

{

	if (!kvm->arch.tdp_mmu_enabled)

		return;

}

arch/x86/kvm/mmu/tdp_mmu.h

0 → 100644
+10 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



#ifndef __KVM_X86_MMU_TDP_MMU_H

#define __KVM_X86_MMU_TDP_MMU_H



#include <linux/kvm_host.h>



void kvm_mmu_init_tdp_mmu(struct kvm *kvm);

void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm);

#endif /* __KVM_X86_MMU_TDP_MMU_H */

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