From 9a558ee3ccb8afcf43c8d9d4d206ab6de4aa30a2 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Mon, 3 Feb 2014 10:42:30 +0100 Subject: [PATCH] KVM: s390: Handle MVPG partial execution interception When the guest executes the MVPG instruction with DAT disabled, and the source or destination page is not mapped in the host, the so-called partial execution interception occurs. We need to handle this event by setting up a mapping for the corresponding user pages. Signed-off-by: Thomas Huth Reviewed-by: Cornelia Huck Signed-off-by: Christian Borntraeger --- arch/s390/kvm/intercept.c | 55 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 54 insertions(+), 1 deletion(-) diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c index 30e1c5eb726a..54313fe6e8d4 100644 --- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -1,7 +1,7 @@ /* * in-kernel handling for sie intercepts * - * Copyright IBM Corp. 2008, 2009 + * Copyright IBM Corp. 2008, 2014 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License (version 2 only) @@ -234,6 +234,58 @@ static int handle_instruction_and_prog(struct kvm_vcpu *vcpu) return rc2; } +/** + * Handle MOVE PAGE partial execution interception. + * + * This interception can only happen for guests with DAT disabled and + * addresses that are currently not mapped in the host. Thus we try to + * set up the mappings for the corresponding user pages here (or throw + * addressing exceptions in case of illegal guest addresses). + */ +static int handle_mvpg_pei(struct kvm_vcpu *vcpu) +{ + unsigned long hostaddr, srcaddr, dstaddr; + psw_t *psw = &vcpu->arch.sie_block->gpsw; + struct mm_struct *mm = current->mm; + int reg1, reg2, rc; + + kvm_s390_get_regs_rre(vcpu, ®1, ®2); + srcaddr = kvm_s390_real_to_abs(vcpu, vcpu->run->s.regs.gprs[reg2]); + dstaddr = kvm_s390_real_to_abs(vcpu, vcpu->run->s.regs.gprs[reg1]); + + /* Make sure that the source is paged-in */ + hostaddr = gmap_fault(srcaddr, vcpu->arch.gmap); + if (IS_ERR_VALUE(hostaddr)) + return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); + down_read(&mm->mmap_sem); + rc = get_user_pages(current, mm, hostaddr, 1, 0, 0, NULL, NULL); + up_read(&mm->mmap_sem); + if (rc < 0) + return rc; + + /* Make sure that the destination is paged-in */ + hostaddr = gmap_fault(dstaddr, vcpu->arch.gmap); + if (IS_ERR_VALUE(hostaddr)) + return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); + down_read(&mm->mmap_sem); + rc = get_user_pages(current, mm, hostaddr, 1, 1, 0, NULL, NULL); + up_read(&mm->mmap_sem); + if (rc < 0) + return rc; + + psw->addr = __rewind_psw(*psw, 4); + + return 0; +} + +static int handle_partial_execution(struct kvm_vcpu *vcpu) +{ + if (vcpu->arch.sie_block->ipa == 0xb254) /* MVPG */ + return handle_mvpg_pei(vcpu); + + return -EOPNOTSUPP; +} + static const intercept_handler_t intercept_funcs[] = { [0x00 >> 2] = handle_noop, [0x04 >> 2] = handle_instruction, @@ -245,6 +297,7 @@ static const intercept_handler_t intercept_funcs[] = { [0x1C >> 2] = kvm_s390_handle_wait, [0x20 >> 2] = handle_validity, [0x28 >> 2] = handle_stop, + [0x38 >> 2] = handle_partial_execution, }; int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu) -- 2.20.1