From 8f2abe6a1e525e878bdf58f68ccd146d543fde84 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Tue, 25 Mar 2008 18:47:23 +0100 Subject: [PATCH] KVM: s390: sie intercept handling This path introduces handling of sie intercepts in three flavors: Intercepts are either handled completely in-kernel by kvm_handle_sie_intercept(), or passed to userspace with corresponding data in struct kvm_run in case kvm_handle_sie_intercept() returns -ENOTSUPP. In case of partial execution in kernel with the need of userspace support, kvm_handle_sie_intercept() may choose to set up struct kvm_run and return -EREMOTE. The trivial intercept reasons are handled in this patch: handle_noop() just does nothing for intercepts that don't require our support at all handle_stop() is called when a cpu enters stopped state, and it drops out to userland after updating our vcpu state handle_validity() faults in the cpu lowcore if needed, or passes the request to userland Acked-by: Martin Schwidefsky Signed-off-by: Christian Borntraeger Signed-off-by: Carsten Otte Signed-off-by: Avi Kivity --- arch/s390/kvm/Makefile | 2 +- arch/s390/kvm/intercept.c | 80 +++++++++++++++++++++++++++++++++++++ arch/s390/kvm/kvm-s390.c | 46 ++++++++++++++++++++- arch/s390/kvm/kvm-s390.h | 7 ++++ include/asm-s390/kvm_host.h | 4 ++ include/linux/kvm.h | 9 +++++ 6 files changed, 146 insertions(+), 2 deletions(-) create mode 100644 arch/s390/kvm/intercept.c diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile index 0d8d1135a27..27882b35ef0 100644 --- a/arch/s390/kvm/Makefile +++ b/arch/s390/kvm/Makefile @@ -10,5 +10,5 @@ common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o) EXTRA_CFLAGS += -Ivirt/kvm -Iarch/s390/kvm -kvm-objs := $(common-objs) kvm-s390.o sie64a.o +kvm-objs := $(common-objs) kvm-s390.o sie64a.o intercept.o obj-$(CONFIG_KVM) += kvm.o diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c new file mode 100644 index 00000000000..e757230b982 --- /dev/null +++ b/arch/s390/kvm/intercept.c @@ -0,0 +1,80 @@ +/* + * intercept.c - in-kernel handling for sie intercepts + * + * Copyright IBM Corp. 2008 + * + * 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) + * as published by the Free Software Foundation. + * + * Author(s): Carsten Otte + * Christian Borntraeger + */ + +#include +#include +#include + +#include + +#include "kvm-s390.h" + +static int handle_noop(struct kvm_vcpu *vcpu) +{ + switch (vcpu->arch.sie_block->icptcode) { + case 0x10: + vcpu->stat.exit_external_request++; + break; + case 0x14: + vcpu->stat.exit_external_interrupt++; + break; + default: + break; /* nothing */ + } + return 0; +} + +static int handle_stop(struct kvm_vcpu *vcpu) +{ + vcpu->stat.exit_stop_request++; + VCPU_EVENT(vcpu, 3, "%s", "cpu stopped"); + atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags); + return -ENOTSUPP; +} + +static int handle_validity(struct kvm_vcpu *vcpu) +{ + int viwhy = vcpu->arch.sie_block->ipb >> 16; + vcpu->stat.exit_validity++; + if (viwhy == 0x37) { + fault_in_pages_writeable((char __user *) + vcpu->kvm->arch.guest_origin + + vcpu->arch.sie_block->prefix, + PAGE_SIZE); + return 0; + } + VCPU_EVENT(vcpu, 2, "unhandled validity intercept code %d", + viwhy); + return -ENOTSUPP; +} + +static const intercept_handler_t intercept_funcs[0x48 >> 2] = { + [0x00 >> 2] = handle_noop, + [0x10 >> 2] = handle_noop, + [0x14 >> 2] = handle_noop, + [0x20 >> 2] = handle_validity, + [0x28 >> 2] = handle_stop, +}; + +int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu) +{ + intercept_handler_t func; + u8 code = vcpu->arch.sie_block->icptcode; + + if (code & 3 || code > 0x48) + return -ENOTSUPP; + func = intercept_funcs[code >> 2]; + if (func) + return func(vcpu); + return -ENOTSUPP; +} diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 6e1e1d39ae1..a906499214b 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -23,12 +23,17 @@ #include #include +#include "kvm-s390.h" #include "gaccess.h" #define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU struct kvm_stats_debugfs_item debugfs_entries[] = { { "userspace_handled", VCPU_STAT(exit_userspace) }, + { "exit_validity", VCPU_STAT(exit_validity) }, + { "exit_stop_request", VCPU_STAT(exit_stop_request) }, + { "exit_external_request", VCPU_STAT(exit_external_request) }, + { "exit_external_interrupt", VCPU_STAT(exit_external_interrupt) }, { NULL } }; @@ -380,6 +385,7 @@ static void __vcpu_run(struct kvm_vcpu *vcpu) int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) { + int rc; sigset_t sigsaved; vcpu_load(vcpu); @@ -389,7 +395,45 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) atomic_set_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags); - __vcpu_run(vcpu); + switch (kvm_run->exit_reason) { + case KVM_EXIT_S390_SIEIC: + vcpu->arch.sie_block->gpsw.mask = kvm_run->s390_sieic.mask; + vcpu->arch.sie_block->gpsw.addr = kvm_run->s390_sieic.addr; + break; + case KVM_EXIT_UNKNOWN: + case KVM_EXIT_S390_RESET: + break; + default: + BUG(); + } + + might_sleep(); + + do { + __vcpu_run(vcpu); + + rc = kvm_handle_sie_intercept(vcpu); + } while (!signal_pending(current) && !rc); + + if (signal_pending(current) && !rc) + rc = -EINTR; + + if (rc == -ENOTSUPP) { + /* intercept cannot be handled in-kernel, prepare kvm-run */ + kvm_run->exit_reason = KVM_EXIT_S390_SIEIC; + kvm_run->s390_sieic.icptcode = vcpu->arch.sie_block->icptcode; + kvm_run->s390_sieic.mask = vcpu->arch.sie_block->gpsw.mask; + kvm_run->s390_sieic.addr = vcpu->arch.sie_block->gpsw.addr; + kvm_run->s390_sieic.ipa = vcpu->arch.sie_block->ipa; + kvm_run->s390_sieic.ipb = vcpu->arch.sie_block->ipb; + rc = 0; + } + + if (rc == -EREMOTE) { + /* intercept was handled, but userspace support is needed + * kvm_run has been prepared by the handler */ + rc = 0; + } if (vcpu->sigset_active) sigprocmask(SIG_SETMASK, &sigsaved, NULL); diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index ed64a22ca86..5b82527b7f8 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -13,6 +13,13 @@ #ifndef ARCH_S390_KVM_S390_H #define ARCH_S390_KVM_S390_H + +#include + +typedef int (*intercept_handler_t)(struct kvm_vcpu *vcpu); + +int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu); + #define VM_EVENT(d_kvm, d_loglevel, d_string, d_args...)\ do { \ debug_sprintf_event(d_kvm->arch.dbf, d_loglevel, d_string "\n", \ diff --git a/include/asm-s390/kvm_host.h b/include/asm-s390/kvm_host.h index c9d65333310..8965b38d0a3 100644 --- a/include/asm-s390/kvm_host.h +++ b/include/asm-s390/kvm_host.h @@ -101,6 +101,10 @@ struct sie_block { struct kvm_vcpu_stat { u32 exit_userspace; + u32 exit_external_request; + u32 exit_external_interrupt; + u32 exit_stop_request; + u32 exit_validity; }; struct kvm_vcpu_arch { diff --git a/include/linux/kvm.h b/include/linux/kvm.h index 2367ff0c5dd..f2acd6b9ab4 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -74,6 +74,7 @@ struct kvm_irqchip { #define KVM_EXIT_INTR 10 #define KVM_EXIT_SET_TPR 11 #define KVM_EXIT_TPR_ACCESS 12 +#define KVM_EXIT_S390_SIEIC 13 /* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */ struct kvm_run { @@ -138,6 +139,14 @@ struct kvm_run { __u32 is_write; __u32 pad; } tpr_access; + /* KVM_EXIT_S390_SIEIC */ + struct { + __u8 icptcode; + __u64 mask; /* psw upper half */ + __u64 addr; /* psw lower half */ + __u16 ipa; + __u32 ipb; + } s390_sieic; /* Fix the size of the union. */ char padding[256]; }; -- 2.41.0