Commit cb210737 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: Pass new routing entries and irqfd when updating IRTEs 

When updating IRTEs in response to a GSI routing or IRQ bypass change,
pass the new/current routing information along with the associated irqfd.
This will allow KVM x86 to harden, simplify, and deduplicate its code.

Since adding/removing a bypass producer is now conveniently protected with
irqfds.lock, i.e. can't run concurrently with kvm_irq_routing_update(),
use the routing information cached in the irqfd instead of looking up
the information in the current GSI routing tables.

Opportunistically convert an existing printk() to pr_info() and put its
string onto a single line (old code that strictly adhered to 80 chars).

Link: https://lore.kernel.org/r/20250611224604.313496-5-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent e76c2745

arch/arm64/kvm/arm.c

+4 −3
Original line number Diff line number Diff line
@@ -2771,8 +2771,9 @@ bool kvm_arch_irqfd_route_changed(struct kvm_kernel_irq_routing_entry *old, 
	return memcmp(&old->msi, &new->msi, sizeof(new->msi));

}



int kvm_arch_update_irqfd_routing(struct kvm *kvm, unsigned int host_irq,

				  uint32_t guest_irq, bool set)

int kvm_arch_update_irqfd_routing(struct kvm_kernel_irqfd *irqfd,

				  struct kvm_kernel_irq_routing_entry *old,

				  struct kvm_kernel_irq_routing_entry *new)

{

	/*

	 * Remapping the vLPI requires taking the its_lock mutex to resolve
@@ -2781,7 +2782,7 @@ int kvm_arch_update_irqfd_routing(struct kvm *kvm, unsigned int host_irq, 
	 *

	 * Unmap the vLPI and fall back to software LPI injection.

	 */

	return kvm_vgic_v4_unset_forwarding(kvm, host_irq);

	return kvm_vgic_v4_unset_forwarding(irqfd->kvm, irqfd->producer->irq);

}



void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)

arch/x86/include/asm/kvm_host.h

+4 −2
Original line number Diff line number Diff line
@@ -297,6 +297,7 @@ enum x86_intercept_stage; 
 */

#define KVM_APIC_PV_EOI_PENDING	1



struct kvm_kernel_irqfd;

struct kvm_kernel_irq_routing_entry;



/*
@@ -1845,8 +1846,9 @@ struct kvm_x86_ops { 
	void (*vcpu_blocking)(struct kvm_vcpu *vcpu);

	void (*vcpu_unblocking)(struct kvm_vcpu *vcpu);



	int (*pi_update_irte)(struct kvm *kvm, unsigned int host_irq,

			      uint32_t guest_irq, bool set);

	int (*pi_update_irte)(struct kvm_kernel_irqfd *irqfd, struct kvm *kvm,

			      unsigned int host_irq, uint32_t guest_irq,

			      struct kvm_kernel_irq_routing_entry *new);

	void (*pi_start_assignment)(struct kvm *kvm);

	void (*apicv_pre_state_restore)(struct kvm_vcpu *vcpu);

	void (*apicv_post_state_restore)(struct kvm_vcpu *vcpu);

arch/x86/kvm/svm/avic.c

+7 −11
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/hashtable.h>

#include <linux/amd-iommu.h>

#include <linux/kvm_host.h>

#include <linux/kvm_irqfd.h>



#include <asm/irq_remapping.h>

#include <asm/msr.h>
@@ -886,21 +887,14 @@ get_pi_vcpu_info(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e, 
	return 0;

}



/*

 * avic_pi_update_irte - set IRTE for Posted-Interrupts

 *

 * @kvm: kvm

 * @host_irq: host irq of the interrupt

 * @guest_irq: gsi of the interrupt

 * @set: set or unset PI

 * returns 0 on success, < 0 on failure

 */

int avic_pi_update_irte(struct kvm *kvm, unsigned int host_irq,

			uint32_t guest_irq, bool set)

int avic_pi_update_irte(struct kvm_kernel_irqfd *irqfd, struct kvm *kvm,

			unsigned int host_irq, uint32_t guest_irq,

			struct kvm_kernel_irq_routing_entry *new)

{

	struct kvm_kernel_irq_routing_entry *e;

	struct kvm_irq_routing_table *irq_rt;

	bool enable_remapped_mode = true;

	bool set = !!new;

	int idx, ret = 0;



	if (!kvm_arch_has_assigned_device(kvm) || !kvm_arch_has_irq_bypass())
@@ -926,6 +920,8 @@ int avic_pi_update_irte(struct kvm *kvm, unsigned int host_irq, 
		if (e->type != KVM_IRQ_ROUTING_MSI)

			continue;



		WARN_ON_ONCE(new && memcmp(e, new, sizeof(*new)));



		/**

		 * Here, we setup with legacy mode in the following cases:

		 * 1. When cannot target interrupt to a specific vcpu.

arch/x86/kvm/svm/svm.h

+3 −2
Original line number Diff line number Diff line
@@ -736,8 +736,9 @@ void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu); 
void avic_vcpu_put(struct kvm_vcpu *vcpu);

void avic_apicv_post_state_restore(struct kvm_vcpu *vcpu);

void avic_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu);

int avic_pi_update_irte(struct kvm *kvm, unsigned int host_irq,

			uint32_t guest_irq, bool set);

int avic_pi_update_irte(struct kvm_kernel_irqfd *irqfd, struct kvm *kvm,

			unsigned int host_irq, uint32_t guest_irq,

			struct kvm_kernel_irq_routing_entry *new);

void avic_vcpu_blocking(struct kvm_vcpu *vcpu);

void avic_vcpu_unblocking(struct kvm_vcpu *vcpu);

void avic_ring_doorbell(struct kvm_vcpu *vcpu);

arch/x86/kvm/vmx/posted_intr.c

+8 −11
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt



#include <linux/kvm_host.h>

#include <linux/kvm_irqfd.h>



#include <asm/irq_remapping.h>

#include <asm/cpu.h>
@@ -294,17 +295,9 @@ void vmx_pi_start_assignment(struct kvm *kvm) 
	kvm_make_all_cpus_request(kvm, KVM_REQ_UNBLOCK);

}



/*

 * vmx_pi_update_irte - set IRTE for Posted-Interrupts

 *

 * @kvm: kvm

 * @host_irq: host irq of the interrupt

 * @guest_irq: gsi of the interrupt

 * @set: set or unset PI

 * returns 0 on success, < 0 on failure

 */

int vmx_pi_update_irte(struct kvm *kvm, unsigned int host_irq,

		       uint32_t guest_irq, bool set)

int vmx_pi_update_irte(struct kvm_kernel_irqfd *irqfd, struct kvm *kvm,

		       unsigned int host_irq, uint32_t guest_irq,

		       struct kvm_kernel_irq_routing_entry *new)

{

	struct kvm_kernel_irq_routing_entry *e;

	struct kvm_irq_routing_table *irq_rt;
@@ -312,6 +305,7 @@ int vmx_pi_update_irte(struct kvm *kvm, unsigned int host_irq, 
	struct kvm_lapic_irq irq;

	struct kvm_vcpu *vcpu;

	struct vcpu_data vcpu_info;

	bool set = !!new;

	int idx, ret = 0;



	if (!vmx_can_use_vtd_pi(kvm))
@@ -329,6 +323,9 @@ int vmx_pi_update_irte(struct kvm *kvm, unsigned int host_irq, 
	hlist_for_each_entry(e, &irq_rt->map[guest_irq], link) {

		if (e->type != KVM_IRQ_ROUTING_MSI)

			continue;



		WARN_ON_ONCE(new && memcmp(e, new, sizeof(*new)));



		/*

		 * VT-d PI cannot support posting multicast/broadcast

		 * interrupts to a vCPU, we still use interrupt remapping