On 06.02.20 11:32, Thomas Huth wrote:
> On 06/02/2020 10.39, Christian Borntraeger wrote:
>> From: Janosch Frank <frankja@xxxxxxxxxxxxx>
>>
>> Now that we can't access guest memory anymore, we have a dedicated
>> sattelite block that's a bounce buffer for instruction data.
>
> s/sattelite/satellite/
>
>> We re-use the memop interface to copy the instruction data to / from
>> userspace. This lets us re-use a lot of QEMU code which used that
>> interface to make logical guest memory accesses which are not possible
>> anymore in protected mode anyway.
>>
>> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
>> ---
>> arch/s390/include/asm/kvm_host.h | 11 ++++++-
>> arch/s390/kvm/kvm-s390.c | 49 ++++++++++++++++++++++++++++++++
>> arch/s390/kvm/pv.c | 9 ++++++
>> include/uapi/linux/kvm.h | 10 +++++--
>> 4 files changed, 76 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
>> index 9d7b248dcadc..2fe8d3c81951 100644
>> --- a/arch/s390/include/asm/kvm_host.h
>> +++ b/arch/s390/include/asm/kvm_host.h
>> @@ -127,6 +127,12 @@ struct mcck_volatile_info {
>> #define CR14_INITIAL_MASK (CR14_UNUSED_32 | CR14_UNUSED_33 | \
>> CR14_EXTERNAL_DAMAGE_SUBMASK)
>>
>> +#define SIDAD_SIZE_MASK 0xff
>> +#define sida_origin(sie_block) \
>> + (sie_block->sidad & PAGE_MASK)
>> +#define sida_size(sie_block) \
>> + (((sie_block->sidad & SIDAD_SIZE_MASK) + 1) * PAGE_SIZE)
>> +
>> #define CPUSTAT_STOPPED 0x80000000
>> #define CPUSTAT_WAIT 0x10000000
>> #define CPUSTAT_ECALL_PEND 0x08000000
>> @@ -315,7 +321,10 @@ struct kvm_s390_sie_block {
>> #define CRYCB_FORMAT2 0x00000003
>> __u32 crycbd; /* 0x00fc */
>> __u64 gcr[16]; /* 0x0100 */
>> - __u64 gbea; /* 0x0180 */
>> + union {
>> + __u64 gbea; /* 0x0180 */
>
> Maybe adjust the spaces before the comment.
>
>> + __u64 sidad;
[...]
ack
>> + switch (mop->op) {
>> + case KVM_S390_MEMOP_SIDA_READ:
>> + r = 0;
>
> r is alread pre-initialized with 0 where it is declared, so you could
> remove the above line.
ack
>
>> + if (copy_to_user(uaddr, (void *)(sida_origin(vcpu->arch.sie_block) +
>> + mop->sida_offset), mop->size))
>> + r = -EFAULT;
>> +
>> + break;
>> + case KVM_S390_MEMOP_SIDA_WRITE:
>> + r = 0;
>
> dito.
>
ack
[...]
>> };
>>
>> -/* for KVM_S390_MEM_OP */
>> +/* for KVM_S390_MEM_OP and KVM_S390_SIDA_OP */
>
> Remove this change now, please.
ack
>
>> struct kvm_s390_mem_op {
>> /* in */
>> __u64 gaddr; /* the guest address */
>> @@ -475,11 +475,17 @@ struct kvm_s390_mem_op {
>> __u32 op; /* type of operation */
>> __u64 buf; /* buffer in userspace */
>> __u8 ar; /* the access register number */
>> - __u8 reserved[31]; /* should be set to 0 */
>> + __u8 reserved21[3]; /* should be set to 0 */
>> + __u32 sida_offset; /* offset into the sida */
>> + __u8 reserved28[24]; /* should be set to 0 */
>> };
>> +
>> +
>> /* types for kvm_s390_mem_op->op */
>> #define KVM_S390_MEMOP_LOGICAL_READ 0
>> #define KVM_S390_MEMOP_LOGICAL_WRITE 1
>> +#define KVM_S390_MEMOP_SIDA_READ 2
>> +#define KVM_S390_MEMOP_SIDA_WRITE 3
>> /* flags for kvm_s390_mem_op->flags */
>> #define KVM_S390_MEMOP_F_CHECK_ONLY (1ULL << 0)
>> #define KVM_S390_MEMOP_F_INJECT_EXCEPTION (1ULL << 1)
>
> With the nits fixed:
> Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx>
thanks
