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linux_dsm_epyc7002/arch/s390/kvm/priv.c
Heiko Carstens db4a29cb6a KVM: s390: fix and enforce return code handling for irq injections 
kvm_s390_inject_program_int() and friends may fail if no memory is available.
This must be reported to the calling functions, so that this gets passed
down to user space which should fix the situation.
Alternatively we end up with guest state corruption.

So fix this and enforce return value checking by adding a __must_check
annotation to all of these function prototypes.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-02 16:14:39 +03:00

588 lines
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/*
* handling privileged instructions
*
* 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 <cotte@de.ibm.com>
* Christian Borntraeger <borntraeger@de.ibm.com>
*/
#include <linux/kvm.h>
#include <linux/gfp.h>
#include <linux/errno.h>
#include <asm/asm-offsets.h>
#include <asm/current.h>
#include <asm/debug.h>
#include <asm/ebcdic.h>
#include <asm/sysinfo.h>
#include <asm/ptrace.h>
#include <asm/compat.h>
#include "gaccess.h"
#include "kvm-s390.h"
#include "trace.h"
static int handle_set_prefix(struct kvm_vcpu *vcpu)
{
u64 operand2;
u32 address = 0;
u8 tmp;
vcpu->stat.instruction_spx++;
operand2 = kvm_s390_get_base_disp_s(vcpu);
/* must be word boundary */
if (operand2 & 3)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
/* get the value */
if (get_guest(vcpu, address, (u32 __user *) operand2))
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
address = address & 0x7fffe000u;
/* make sure that the new value is valid memory */
if (copy_from_guest_absolute(vcpu, &tmp, address, 1) ||
(copy_from_guest_absolute(vcpu, &tmp, address + PAGE_SIZE, 1)))
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
kvm_s390_set_prefix(vcpu, address);
VCPU_EVENT(vcpu, 5, "setting prefix to %x", address);
trace_kvm_s390_handle_prefix(vcpu, 1, address);
return 0;
}
static int handle_store_prefix(struct kvm_vcpu *vcpu)
{
u64 operand2;
u32 address;
vcpu->stat.instruction_stpx++;
operand2 = kvm_s390_get_base_disp_s(vcpu);
/* must be word boundary */
if (operand2 & 3)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
address = vcpu->arch.sie_block->prefix;
address = address & 0x7fffe000u;
/* get the value */
if (put_guest(vcpu, address, (u32 __user *)operand2))
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
VCPU_EVENT(vcpu, 5, "storing prefix to %x", address);
trace_kvm_s390_handle_prefix(vcpu, 0, address);
return 0;
}
static int handle_store_cpu_address(struct kvm_vcpu *vcpu)
{
u64 useraddr;
vcpu->stat.instruction_stap++;
useraddr = kvm_s390_get_base_disp_s(vcpu);
if (useraddr & 1)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
if (put_guest(vcpu, vcpu->vcpu_id, (u16 __user *)useraddr))
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
VCPU_EVENT(vcpu, 5, "storing cpu address to %llx", useraddr);
trace_kvm_s390_handle_stap(vcpu, useraddr);
return 0;
}
static int handle_skey(struct kvm_vcpu *vcpu)
{
vcpu->stat.instruction_storage_key++;
vcpu->arch.sie_block->gpsw.addr -= 4;
VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
return 0;
}
static int handle_tpi(struct kvm_vcpu *vcpu)
{
struct kvm_s390_interrupt_info *inti;
u64 addr;
int cc;
addr = kvm_s390_get_base_disp_s(vcpu);
if (addr & 3)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
cc = 0;
inti = kvm_s390_get_io_int(vcpu->kvm, vcpu->run->s.regs.crs[6], 0);
if (!inti)
goto no_interrupt;
cc = 1;
if (addr) {
/*
* Store the two-word I/O interruption code into the
* provided area.
*/
put_guest(vcpu, inti->io.subchannel_id, (u16 __user *) addr);
put_guest(vcpu, inti->io.subchannel_nr, (u16 __user *) (addr + 2));
put_guest(vcpu, inti->io.io_int_parm, (u32 __user *) (addr + 4));
} else {
/*
* Store the three-word I/O interruption code into
* the appropriate lowcore area.
*/
put_guest(vcpu, inti->io.subchannel_id, (u16 __user *) __LC_SUBCHANNEL_ID);
put_guest(vcpu, inti->io.subchannel_nr, (u16 __user *) __LC_SUBCHANNEL_NR);
put_guest(vcpu, inti->io.io_int_parm, (u32 __user *) __LC_IO_INT_PARM);
put_guest(vcpu, inti->io.io_int_word, (u32 __user *) __LC_IO_INT_WORD);
}
kfree(inti);
no_interrupt:
/* Set condition code and we're done. */
vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
vcpu->arch.sie_block->gpsw.mask |= (cc & 3ul) << 44;
return 0;
}
static int handle_tsch(struct kvm_vcpu *vcpu)
{
struct kvm_s390_interrupt_info *inti;
inti = kvm_s390_get_io_int(vcpu->kvm, 0,
vcpu->run->s.regs.gprs[1]);
/*
* Prepare exit to userspace.
* We indicate whether we dequeued a pending I/O interrupt
* so that userspace can re-inject it if the instruction gets
* a program check. While this may re-order the pending I/O
* interrupts, this is no problem since the priority is kept
* intact.
*/
vcpu->run->exit_reason = KVM_EXIT_S390_TSCH;
vcpu->run->s390_tsch.dequeued = !!inti;
if (inti) {
vcpu->run->s390_tsch.subchannel_id = inti->io.subchannel_id;
vcpu->run->s390_tsch.subchannel_nr = inti->io.subchannel_nr;
vcpu->run->s390_tsch.io_int_parm = inti->io.io_int_parm;
vcpu->run->s390_tsch.io_int_word = inti->io.io_int_word;
}
vcpu->run->s390_tsch.ipb = vcpu->arch.sie_block->ipb;
kfree(inti);
return -EREMOTE;
}
static int handle_io_inst(struct kvm_vcpu *vcpu)
{
VCPU_EVENT(vcpu, 4, "%s", "I/O instruction");
if (vcpu->kvm->arch.css_support) {
/*
* Most I/O instructions will be handled by userspace.
* Exceptions are tpi and the interrupt portion of tsch.
*/
if (vcpu->arch.sie_block->ipa == 0xb236)
return handle_tpi(vcpu);
if (vcpu->arch.sie_block->ipa == 0xb235)
return handle_tsch(vcpu);
/* Handle in userspace. */
return -EOPNOTSUPP;
} else {
/*
* Set condition code 3 to stop the guest from issueing channel
* I/O instructions.
*/
vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
vcpu->arch.sie_block->gpsw.mask |= (3 & 3ul) << 44;
return 0;
}
}
static int handle_stfl(struct kvm_vcpu *vcpu)
{
unsigned int facility_list;
int rc;
vcpu->stat.instruction_stfl++;
/* only pass the facility bits, which we can handle */
facility_list = S390_lowcore.stfl_fac_list & 0xff00fff3;
rc = copy_to_guest(vcpu, offsetof(struct _lowcore, stfl_fac_list),
&facility_list, sizeof(facility_list));
if (rc)
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
VCPU_EVENT(vcpu, 5, "store facility list value %x", facility_list);
trace_kvm_s390_handle_stfl(vcpu, facility_list);
return 0;
}
static void handle_new_psw(struct kvm_vcpu *vcpu)
{
/* Check whether the new psw is enabled for machine checks. */
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_MCHECK)
kvm_s390_deliver_pending_machine_checks(vcpu);
}
#define PSW_MASK_ADDR_MODE (PSW_MASK_EA | PSW_MASK_BA)
#define PSW_MASK_UNASSIGNED 0xb80800fe7fffffffUL
#define PSW_ADDR_24 0x0000000000ffffffUL
#define PSW_ADDR_31 0x000000007fffffffUL
static int is_valid_psw(psw_t *psw) {
if (psw->mask & PSW_MASK_UNASSIGNED)
return 0;
if ((psw->mask & PSW_MASK_ADDR_MODE) == PSW_MASK_BA) {
if (psw->addr & ~PSW_ADDR_31)
return 0;
}
if (!(psw->mask & PSW_MASK_ADDR_MODE) && (psw->addr & ~PSW_ADDR_24))
return 0;
if ((psw->mask & PSW_MASK_ADDR_MODE) == PSW_MASK_EA)
return 0;
return 1;
}
int kvm_s390_handle_lpsw(struct kvm_vcpu *vcpu)
{
psw_t *gpsw = &vcpu->arch.sie_block->gpsw;
psw_compat_t new_psw;
u64 addr;
if (gpsw->mask & PSW_MASK_PSTATE)
return kvm_s390_inject_program_int(vcpu,
PGM_PRIVILEGED_OPERATION);
addr = kvm_s390_get_base_disp_s(vcpu);
if (addr & 7)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
if (copy_from_guest(vcpu, &new_psw, addr, sizeof(new_psw)))
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
if (!(new_psw.mask & PSW32_MASK_BASE))
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
gpsw->mask = (new_psw.mask & ~PSW32_MASK_BASE) << 32;
gpsw->mask |= new_psw.addr & PSW32_ADDR_AMODE;
gpsw->addr = new_psw.addr & ~PSW32_ADDR_AMODE;
if (!is_valid_psw(gpsw))
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
handle_new_psw(vcpu);
return 0;
}
static int handle_lpswe(struct kvm_vcpu *vcpu)
{
psw_t new_psw;
u64 addr;
addr = kvm_s390_get_base_disp_s(vcpu);
if (addr & 7)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
if (copy_from_guest(vcpu, &new_psw, addr, sizeof(new_psw)))
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
vcpu->arch.sie_block->gpsw = new_psw;
if (!is_valid_psw(&vcpu->arch.sie_block->gpsw))
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
handle_new_psw(vcpu);
return 0;
}
static int handle_stidp(struct kvm_vcpu *vcpu)
{
u64 operand2;
vcpu->stat.instruction_stidp++;
operand2 = kvm_s390_get_base_disp_s(vcpu);
if (operand2 & 7)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
if (put_guest(vcpu, vcpu->arch.stidp_data, (u64 __user *)operand2))
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
VCPU_EVENT(vcpu, 5, "%s", "store cpu id");
return 0;
}
static void handle_stsi_3_2_2(struct kvm_vcpu *vcpu, struct sysinfo_3_2_2 *mem)
{
struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
int cpus = 0;
int n;
spin_lock(&fi->lock);
for (n = 0; n < KVM_MAX_VCPUS; n++)
if (fi->local_int[n])
cpus++;
spin_unlock(&fi->lock);
/* deal with other level 3 hypervisors */
if (stsi(mem, 3, 2, 2))
mem->count = 0;
if (mem->count < 8)
mem->count++;
for (n = mem->count - 1; n > 0 ; n--)
memcpy(&mem->vm[n], &mem->vm[n - 1], sizeof(mem->vm[0]));
mem->vm[0].cpus_total = cpus;
mem->vm[0].cpus_configured = cpus;
mem->vm[0].cpus_standby = 0;
mem->vm[0].cpus_reserved = 0;
mem->vm[0].caf = 1000;
memcpy(mem->vm[0].name, "KVMguest", 8);
ASCEBC(mem->vm[0].name, 8);
memcpy(mem->vm[0].cpi, "KVM/Linux ", 16);
ASCEBC(mem->vm[0].cpi, 16);
}
static int handle_stsi(struct kvm_vcpu *vcpu)
{
int fc = (vcpu->run->s.regs.gprs[0] & 0xf0000000) >> 28;
int sel1 = vcpu->run->s.regs.gprs[0] & 0xff;
int sel2 = vcpu->run->s.regs.gprs[1] & 0xffff;
u64 operand2;
unsigned long mem;
int rc = 0;
vcpu->stat.instruction_stsi++;
VCPU_EVENT(vcpu, 4, "stsi: fc: %x sel1: %x sel2: %x", fc, sel1, sel2);
operand2 = kvm_s390_get_base_disp_s(vcpu);
if (operand2 & 0xfff && fc > 0)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
switch (fc) {
case 0:
vcpu->run->s.regs.gprs[0] = 3 << 28;
vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
return 0;
case 1: /* same handling for 1 and 2 */
case 2:
mem = get_zeroed_page(GFP_KERNEL);
if (!mem)
goto out_fail;
if (stsi((void *) mem, fc, sel1, sel2))
goto out_mem;
break;
case 3:
if (sel1 != 2 || sel2 != 2)
goto out_fail;
mem = get_zeroed_page(GFP_KERNEL);
if (!mem)
goto out_fail;
handle_stsi_3_2_2(vcpu, (void *) mem);
break;
default:
goto out_fail;
}
if (copy_to_guest_absolute(vcpu, operand2, (void *) mem, PAGE_SIZE)) {
rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
goto out_mem;
}
trace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);
free_page(mem);
vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
vcpu->run->s.regs.gprs[0] = 0;
return 0;
out_mem:
free_page(mem);
out_fail:
/* condition code 3 */
vcpu->arch.sie_block->gpsw.mask |= 3ul << 44;
return rc;
}
static const intercept_handler_t b2_handlers[256] = {
[0x02] = handle_stidp,
[0x10] = handle_set_prefix,
[0x11] = handle_store_prefix,
[0x12] = handle_store_cpu_address,
[0x29] = handle_skey,
[0x2a] = handle_skey,
[0x2b] = handle_skey,
[0x30] = handle_io_inst,
[0x31] = handle_io_inst,
[0x32] = handle_io_inst,
[0x33] = handle_io_inst,
[0x34] = handle_io_inst,
[0x35] = handle_io_inst,
[0x36] = handle_io_inst,
[0x37] = handle_io_inst,
[0x38] = handle_io_inst,
[0x39] = handle_io_inst,
[0x3a] = handle_io_inst,
[0x3b] = handle_io_inst,
[0x3c] = handle_io_inst,
[0x5f] = handle_io_inst,
[0x74] = handle_io_inst,
[0x76] = handle_io_inst,
[0x7d] = handle_stsi,
[0xb1] = handle_stfl,
[0xb2] = handle_lpswe,
};
int kvm_s390_handle_b2(struct kvm_vcpu *vcpu)
{
intercept_handler_t handler;
/*
* a lot of B2 instructions are priviledged. We first check for
* the privileged ones, that we can handle in the kernel. If the
* kernel can handle this instruction, we check for the problem
* state bit and (a) handle the instruction or (b) send a code 2
* program check.
* Anything else goes to userspace.*/
handler = b2_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
if (handler) {
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
return kvm_s390_inject_program_int(vcpu,
PGM_PRIVILEGED_OPERATION);
else
return handler(vcpu);
}
return -EOPNOTSUPP;
}
static int handle_epsw(struct kvm_vcpu *vcpu)
{
int reg1, reg2;
reg1 = (vcpu->arch.sie_block->ipb & 0x00f00000) >> 24;
reg2 = (vcpu->arch.sie_block->ipb & 0x000f0000) >> 16;
/* This basically extracts the mask half of the psw. */
vcpu->run->s.regs.gprs[reg1] &= 0xffffffff00000000;
vcpu->run->s.regs.gprs[reg1] |= vcpu->arch.sie_block->gpsw.mask >> 32;
if (reg2) {
vcpu->run->s.regs.gprs[reg2] &= 0xffffffff00000000;
vcpu->run->s.regs.gprs[reg2] |=
vcpu->arch.sie_block->gpsw.mask & 0x00000000ffffffff;
}
return 0;
}
static const intercept_handler_t b9_handlers[256] = {
[0x8d] = handle_epsw,
[0x9c] = handle_io_inst,
};
int kvm_s390_handle_b9(struct kvm_vcpu *vcpu)
{
intercept_handler_t handler;
/* This is handled just as for the B2 instructions. */
handler = b9_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
if (handler) {
if ((handler != handle_epsw) &&
(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE))
return kvm_s390_inject_program_int(vcpu,
PGM_PRIVILEGED_OPERATION);
else
return handler(vcpu);
}
return -EOPNOTSUPP;
}
static const intercept_handler_t eb_handlers[256] = {
[0x8a] = handle_io_inst,
};
int kvm_s390_handle_priv_eb(struct kvm_vcpu *vcpu)
{
intercept_handler_t handler;
/* All eb instructions that end up here are privileged. */
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
return kvm_s390_inject_program_int(vcpu,
PGM_PRIVILEGED_OPERATION);
handler = eb_handlers[vcpu->arch.sie_block->ipb & 0xff];
if (handler)
return handler(vcpu);
return -EOPNOTSUPP;
}
static int handle_tprot(struct kvm_vcpu *vcpu)
{
u64 address1, address2;
struct vm_area_struct *vma;
unsigned long user_address;
vcpu->stat.instruction_tprot++;
kvm_s390_get_base_disp_sse(vcpu, &address1, &address2);
/* we only handle the Linux memory detection case:
* access key == 0
* guest DAT == off
* everything else goes to userspace. */
if (address2 & 0xf0)
return -EOPNOTSUPP;
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)
return -EOPNOTSUPP;
down_read(&current->mm->mmap_sem);
user_address = __gmap_translate(address1, vcpu->arch.gmap);
if (IS_ERR_VALUE(user_address))
goto out_inject;
vma = find_vma(current->mm, user_address);
if (!vma)
goto out_inject;
vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
if (!(vma->vm_flags & VM_WRITE) && (vma->vm_flags & VM_READ))
vcpu->arch.sie_block->gpsw.mask |= (1ul << 44);
if (!(vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_READ))
vcpu->arch.sie_block->gpsw.mask |= (2ul << 44);
up_read(&current->mm->mmap_sem);
return 0;
out_inject:
up_read(&current->mm->mmap_sem);
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
}
int kvm_s390_handle_e5(struct kvm_vcpu *vcpu)
{
/* For e5xx... instructions we only handle TPROT */
if ((vcpu->arch.sie_block->ipa & 0x00ff) == 0x01)
return handle_tprot(vcpu);
return -EOPNOTSUPP;
}
static int handle_sckpf(struct kvm_vcpu *vcpu)
{
u32 value;
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
return kvm_s390_inject_program_int(vcpu,
PGM_PRIVILEGED_OPERATION);
if (vcpu->run->s.regs.gprs[0] & 0x00000000ffff0000)
return kvm_s390_inject_program_int(vcpu,
PGM_SPECIFICATION);
value = vcpu->run->s.regs.gprs[0] & 0x000000000000ffff;
vcpu->arch.sie_block->todpr = value;
return 0;
}
static const intercept_handler_t x01_handlers[256] = {
[0x07] = handle_sckpf,
};
int kvm_s390_handle_01(struct kvm_vcpu *vcpu)
{
intercept_handler_t handler;
handler = x01_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
if (handler)
return handler(vcpu);
return -EOPNOTSUPP;
}
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