Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1b7029be authored by David Hildenbrand's avatar David Hildenbrand Committed by Christian Borntraeger
Browse files

KVM: s390: vsie: try to refault after a reported fault to g2 



We can avoid one unneeded SIE entry after we reported a fault to g2.
Theoretically, g2 resolves the fault and we can create the shadow mapping
directly, instead of failing again when entering the SIE.

Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 7fd7f39d

arch/s390/kvm/vsie.c

+23 −1
Original line number Diff line number Diff line
@@ -28,7 +28,9 @@ struct vsie_page { 
	struct kvm_s390_sie_block *scb_o;	/* 0x0200 */

	/* the shadow gmap in use by the vsie_page */

	struct gmap *gmap;			/* 0x0208 */

	__u8 reserved[0x0700 - 0x0210];		/* 0x0210 */

	/* address of the last reported fault to guest2 */

	unsigned long fault_addr;		/* 0x0210 */

	__u8 reserved[0x0700 - 0x0218];		/* 0x0218 */

	struct kvm_s390_crypto_cb crycb;	/* 0x0700 */

	__u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE];	/* 0x0800 */

} __packed;
@@ -676,10 +678,27 @@ static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 
		rc = inject_fault(vcpu, rc,

				  current->thread.gmap_addr,

				  current->thread.gmap_write_flag);

		if (rc >= 0)

			vsie_page->fault_addr = current->thread.gmap_addr;

	}

	return rc;

}



/*

 * Retry the previous fault that required guest 2 intervention. This avoids

 * one superfluous SIE re-entry and direct exit.

 *

 * Will ignore any errors. The next SIE fault will do proper fault handling.

 */

static void handle_last_fault(struct kvm_vcpu *vcpu,

			      struct vsie_page *vsie_page)

{

	if (vsie_page->fault_addr)

		kvm_s390_shadow_fault(vcpu, vsie_page->gmap,

				      vsie_page->fault_addr);

	vsie_page->fault_addr = 0;

}



static inline void clear_vsie_icpt(struct vsie_page *vsie_page)

{

	vsie_page->scb_s.icptcode = 0;
@@ -737,6 +756,8 @@ static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 
	struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;

	int rc;



	handle_last_fault(vcpu, vsie_page);



	if (need_resched())

		schedule();

	if (test_cpu_flag(CIF_MCCK_PENDING))
@@ -928,6 +949,7 @@ static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr) 
	vsie_page = page_to_virt(page);

	memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block));

	release_gmap_shadow(vsie_page);

	vsie_page->fault_addr = 0;

	vsie_page->scb_s.ihcpu = 0xffffU;

	return vsie_page;

}