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KVM: s390: convert handle_tpi() 

Convert handle_tpi() to new guest access functions.

The code now sets up a structure which is copied with a single call to
guest space instead of issuing several separate guest access calls.
This is necessary since the to be copied data may cross a page boundary.
If a protection exception happens while accessing any of the pages, the
instruction is suppressed and may not have modified any memory contents.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
Heiko Carstens 2014-01-01 16:55:48 +01:00 committed by Christian Borntraeger
parent ef23e7790e
commit 4799b557c9
1 changed files with 17 additions and 11 deletions
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28
arch/s390/kvm/priv.c
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@ -224,9 +224,12 @@ static int handle_test_block(struct kvm_vcpu *vcpu)
static int handle_tpi(struct kvm_vcpu *vcpu)
{
struct kvm_s390_interrupt_info *inti;
unsigned long len;
u32 tpi_data[3];
int cc, rc;
u64 addr;
int cc;
rc = 0;
addr = kvm_s390_get_base_disp_s(vcpu);
if (addr & 3)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
@ -235,30 +238,33 @@ static int handle_tpi(struct kvm_vcpu *vcpu)
if (!inti)
goto no_interrupt;
cc = 1;
tpi_data[0] = inti->io.subchannel_id << 16 | inti->io.subchannel_nr;
tpi_data[1] = inti->io.io_int_parm;
tpi_data[2] = inti->io.io_int_word;
if (addr) {
/*
* Store the two-word I/O interruption code into the
* provided area.
*/
if (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)))
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
len = sizeof(tpi_data) - 4;
rc = write_guest(vcpu, addr, &tpi_data, len);
if (rc)
return kvm_s390_inject_prog_cond(vcpu, rc);
} 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);
len = sizeof(tpi_data);
if (write_guest_lc(vcpu, __LC_SUBCHANNEL_ID, &tpi_data, len))
rc = -EFAULT;
}
kfree(inti);
no_interrupt:
/* Set condition code and we're done. */
kvm_s390_set_psw_cc(vcpu, cc);
return 0;
if (!rc)
kvm_s390_set_psw_cc(vcpu, cc);
return rc ? -EFAULT : 0;
}
static int handle_tsch(struct kvm_vcpu *vcpu)