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KVM: s390: handle missing storage-key facility

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Without the storage-key facility, SIE won't interpret SSKE, ISKE and
RRBE for us. So let's add proper interception handlers that will be called
if lazy sske cannot be enabled.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
David Hildenbrand
2016-05-10 09:50:21 +02:00
committed by Christian Borntraeger
parent 11ddcd41bc
commit a7e19ab55f
4 changed files with 184 additions and 11 deletions
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150
arch/s390/kvm/priv.c
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@@ -27,6 +27,7 @@
#include <asm/io.h>
#include <asm/ptrace.h>
#include <asm/compat.h>
#include <asm/sclp.h>
#include "gaccess.h"
#include "kvm-s390.h"
#include "trace.h"
@@ -164,8 +165,7 @@ static int __skey_check_enable(struct kvm_vcpu *vcpu)
return rc;
}
static int handle_skey(struct kvm_vcpu *vcpu)
static int try_handle_skey(struct kvm_vcpu *vcpu)
{
int rc;
@@ -173,12 +173,146 @@ static int handle_skey(struct kvm_vcpu *vcpu)
rc = __skey_check_enable(vcpu);
if (rc)
return rc;
if (sclp.has_skey) {
/* with storage-key facility, SIE interprets it for us */
kvm_s390_retry_instr(vcpu);
VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
return -EAGAIN;
}
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
return 0;
}
kvm_s390_retry_instr(vcpu);
VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
static int handle_iske(struct kvm_vcpu *vcpu)
{
unsigned long addr;
unsigned char key;
int reg1, reg2;
int rc;
rc = try_handle_skey(vcpu);
if (rc)
return rc != -EAGAIN ? rc : 0;
kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
addr = vcpu->run->s.regs.gprs[reg2] & PAGE_MASK;
addr = kvm_s390_logical_to_effective(vcpu, addr);
addr = kvm_s390_real_to_abs(vcpu, addr);
addr = gfn_to_hva(vcpu->kvm, gpa_to_gfn(addr));
if (kvm_is_error_hva(addr))
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
down_read(&current->mm->mmap_sem);
rc = get_guest_storage_key(current->mm, addr, &key);
up_read(&current->mm->mmap_sem);
if (rc)
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
vcpu->run->s.regs.gprs[reg1] &= ~0xff;
vcpu->run->s.regs.gprs[reg1] |= key;
return 0;
}
static int handle_rrbe(struct kvm_vcpu *vcpu)
{
unsigned long addr;
int reg1, reg2;
int rc;
rc = try_handle_skey(vcpu);
if (rc)
return rc != -EAGAIN ? rc : 0;
kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
addr = vcpu->run->s.regs.gprs[reg2] & PAGE_MASK;
addr = kvm_s390_logical_to_effective(vcpu, addr);
addr = kvm_s390_real_to_abs(vcpu, addr);
addr = gfn_to_hva(vcpu->kvm, gpa_to_gfn(addr));
if (kvm_is_error_hva(addr))
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
down_read(&current->mm->mmap_sem);
rc = reset_guest_reference_bit(current->mm, addr);
up_read(&current->mm->mmap_sem);
if (rc < 0)
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
kvm_s390_set_psw_cc(vcpu, rc);
return 0;
}
#define SSKE_NQ 0x8
#define SSKE_MR 0x4
#define SSKE_MC 0x2
#define SSKE_MB 0x1
static int handle_sske(struct kvm_vcpu *vcpu)
{
unsigned char m3 = vcpu->arch.sie_block->ipb >> 28;
unsigned long start, end;
unsigned char key, oldkey;
int reg1, reg2;
int rc;
rc = try_handle_skey(vcpu);
if (rc)
return rc != -EAGAIN ? rc : 0;
if (!test_kvm_facility(vcpu->kvm, 8))
m3 &= ~SSKE_MB;
if (!test_kvm_facility(vcpu->kvm, 10))
m3 &= ~(SSKE_MC | SSKE_MR);
if (!test_kvm_facility(vcpu->kvm, 14))
m3 &= ~SSKE_NQ;
kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
key = vcpu->run->s.regs.gprs[reg1] & 0xfe;
start = vcpu->run->s.regs.gprs[reg2] & PAGE_MASK;
start = kvm_s390_logical_to_effective(vcpu, start);
if (m3 & SSKE_MB) {
/* start already designates an absolute address */
end = (start + (1UL << 20)) & ~((1UL << 20) - 1);
} else {
start = kvm_s390_real_to_abs(vcpu, start);
end = start + PAGE_SIZE;
}
while (start != end) {
unsigned long addr = gfn_to_hva(vcpu->kvm, gpa_to_gfn(start));
if (kvm_is_error_hva(addr))
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
down_read(&current->mm->mmap_sem);
rc = cond_set_guest_storage_key(current->mm, addr, key, &oldkey,
m3 & SSKE_NQ, m3 & SSKE_MR,
m3 & SSKE_MC);
up_read(&current->mm->mmap_sem);
if (rc < 0)
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
start += PAGE_SIZE;
};
if (m3 & (SSKE_MC | SSKE_MR)) {
if (m3 & SSKE_MB) {
/* skey in reg1 is unpredictable */
kvm_s390_set_psw_cc(vcpu, 3);
} else {
kvm_s390_set_psw_cc(vcpu, rc);
vcpu->run->s.regs.gprs[reg1] &= ~0xff00UL;
vcpu->run->s.regs.gprs[reg1] |= (u64) oldkey << 8;
}
}
if (m3 & SSKE_MB) {
if (psw_bits(vcpu->arch.sie_block->gpsw).eaba == PSW_AMODE_64BIT)
vcpu->run->s.regs.gprs[reg2] &= ~PAGE_MASK;
else
vcpu->run->s.regs.gprs[reg2] &= ~0xfffff000UL;
end = kvm_s390_logical_to_effective(vcpu, end);
vcpu->run->s.regs.gprs[reg2] |= end;
}
return 0;
}
@@ -586,9 +720,9 @@ static const intercept_handler_t b2_handlers[256] = {
[0x11] = handle_store_prefix,
[0x12] = handle_store_cpu_address,
[0x21] = handle_ipte_interlock,
[0x29] = handle_skey,
[0x2a] = handle_skey,
[0x2b] = handle_skey,
[0x29] = handle_iske,
[0x2a] = handle_rrbe,
[0x2b] = handle_sske,
[0x2c] = handle_test_block,
[0x30] = handle_io_inst,
[0x31] = handle_io_inst,