Commit 6d3da241 authored by Jens Freimann's avatar Jens Freimann Committed by Christian Borntraeger
Browse files

KVM: s390: deliver floating interrupts in order of priority 



This patch makes interrupt handling compliant to the z/Architecture
Principles of Operation with regard to interrupt priorities.

Add a bitmap for pending floating interrupts. Each bit relates to a
interrupt type and its list. A turned on bit indicates that a list
contains items (interrupts) which need to be delivered.  When delivering
interrupts on a cpu we can merge the existing bitmap for cpu-local
interrupts and floating interrupts and have a single mechanism for
delivery.
Currently we have one list for all kinds of floating interrupts and a
corresponding spin lock. This patch adds a separate list per
interrupt type. An exception to this are service signal and machine check
interrupts, as there can be only one pending interrupt at a time.

Signed-off-by: default avatarJens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
parent 94aa033e

arch/s390/include/asm/kvm_host.h

+27 −3
Original line number Diff line number Diff line
@@ -344,6 +344,11 @@ enum irq_types { 
	IRQ_PEND_COUNT

};



/* We have 2M for virtio device descriptor pages. Smallest amount of

 * memory per page is 24 bytes (1 queue), so (2048*1024) / 24 = 87381

 */

#define KVM_S390_MAX_VIRTIO_IRQS 87381



/*

 * Repressible (non-floating) machine check interrupts

 * subclass bits in MCIC
@@ -421,13 +426,32 @@ struct kvm_s390_local_interrupt { 
	unsigned long pending_irqs;

};



#define FIRQ_LIST_IO_ISC_0 0

#define FIRQ_LIST_IO_ISC_1 1

#define FIRQ_LIST_IO_ISC_2 2

#define FIRQ_LIST_IO_ISC_3 3

#define FIRQ_LIST_IO_ISC_4 4

#define FIRQ_LIST_IO_ISC_5 5

#define FIRQ_LIST_IO_ISC_6 6

#define FIRQ_LIST_IO_ISC_7 7

#define FIRQ_LIST_PFAULT   8

#define FIRQ_LIST_VIRTIO   9

#define FIRQ_LIST_COUNT   10

#define FIRQ_CNTR_IO       0

#define FIRQ_CNTR_SERVICE  1

#define FIRQ_CNTR_VIRTIO   2

#define FIRQ_CNTR_PFAULT   3

#define FIRQ_MAX_COUNT     4



struct kvm_s390_float_interrupt {

	unsigned long pending_irqs;

	spinlock_t lock;

	struct list_head list;

	atomic_t active;

	struct list_head lists[FIRQ_LIST_COUNT];

	int counters[FIRQ_MAX_COUNT];

	struct kvm_s390_mchk_info mchk;

	struct kvm_s390_ext_info srv_signal;

	int next_rr_cpu;

	unsigned long idle_mask[BITS_TO_LONGS(KVM_MAX_VCPUS)];

	unsigned int irq_count;

};



struct kvm_hw_wp_info_arch {

arch/s390/kvm/interrupt.c

+473 −359

File changed.

Preview size limit exceeded, changes collapsed.

arch/s390/kvm/kvm-s390.c

+3 −1
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
#include <asm/pgtable.h>

#include <asm/nmi.h>

#include <asm/switch_to.h>

#include <asm/isc.h>

#include <asm/sclp.h>

#include "kvm-s390.h"

#include "gaccess.h"
@@ -1069,7 +1070,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) 
		goto out_err;



	spin_lock_init(&kvm->arch.float_int.lock);

	INIT_LIST_HEAD(&kvm->arch.float_int.list);

	for (i = 0; i < FIRQ_LIST_COUNT; i++)

		INIT_LIST_HEAD(&kvm->arch.float_int.lists[i]);

	init_waitqueue_head(&kvm->arch.ipte_wq);

	mutex_init(&kvm->arch.ipte_mutex);

arch/s390/kvm/kvm-s390.h

+1 −1
Original line number Diff line number Diff line
@@ -178,7 +178,7 @@ int __must_check kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu, 
				      struct kvm_s390_irq *irq);

int __must_check kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code);

struct kvm_s390_interrupt_info *kvm_s390_get_io_int(struct kvm *kvm,

						    u64 cr6, u64 schid);

						    u64 isc_mask, u32 schid);

int kvm_s390_reinject_io_int(struct kvm *kvm,

			     struct kvm_s390_interrupt_info *inti);

int kvm_s390_mask_adapter(struct kvm *kvm, unsigned int id, bool masked);

arch/s390/kvm/priv.c

+6 −3
Original line number Diff line number Diff line
@@ -294,9 +294,12 @@ reinject_interrupt: 


static int handle_tsch(struct kvm_vcpu *vcpu)

{

	struct kvm_s390_interrupt_info *inti;

	struct kvm_s390_interrupt_info *inti = NULL;

	const u64 isc_mask = 0xffUL << 24; /* all iscs set */



	inti = kvm_s390_get_io_int(vcpu->kvm, 0,

	/* a valid schid has at least one bit set */

	if (vcpu->run->s.regs.gprs[1])

		inti = kvm_s390_get_io_int(vcpu->kvm, isc_mask,

					   vcpu->run->s.regs.gprs[1]);



	/*

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