s390x/tcg: properly implement the TOD

Right now, each CPU has its own TOD. Especially, the TOD will differ
based on creation time of a CPU - e.g. when hotplugging a CPU the times
will differ quite a lot, resulting in stall warnings in the guest.

Let's use a single TOD by implementing our new TOD device. Prepare it
for TOD-clock epoch extension.

Most importantly, whenever we set the TOD, we have to update the CKC
timer.

Introduce "tcg_s390x.h" just like "kvm_s390x.h" for tcg specific
function declarations that should not go into cpu.h.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180627134410.4901-6-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
This commit is contained in:
David Hildenbrand 2018-06-27 15:44:06 +02:00 committed by Cornelia Huck
parent f777b20544
commit 7de3b1cdc6
8 changed files with 109 additions and 34 deletions

View file

@ -30,6 +30,9 @@ typedef struct S390TOD {
typedef struct S390TODState {
/* private */
DeviceState parent_obj;
/* unused by KVM implementation */
S390TOD base;
} S390TODState;
typedef struct S390TODClass {
@ -41,6 +44,22 @@ typedef struct S390TODClass {
void (*set)(S390TODState *td, const S390TOD *tod, Error **errp);
} S390TODClass;
/* The value of the TOD clock for 1.1.1970. */
#define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
/* Converts ns to s390's clock format */
static inline uint64_t time2tod(uint64_t ns)
{
return (ns << 9) / 125 + (((ns & 0xff10000000000000ull) / 125) << 9);
}
/* Converts s390's clock format to ns */
static inline uint64_t tod2time(uint64_t t)
{
return ((t >> 9) * 125) + (((t & 0x1ff) * 125) >> 9);
}
void s390_init_tod(void);
S390TODState *s390_get_todstate(void);
#endif