On 07.02.20 12:39, Christian Borntraeger wrote:
> From: Janosch Frank <frankja@xxxxxxxxxxxxx>
>
> This add 2 new variants of the UV CALL.
>
> The first variant handles UV CALLs that might have longer busy
> conditions or just need longer when doing partial completion. We should
> schedule when necessary.
>
> The second variant handles UV CALLs that only need the handle but have
> no payload (e.g. destroying a VM). We can provide a simple wrapper for
> those.
>
> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
> [borntraeger@xxxxxxxxxx: patch merging, splitting, fixing]
> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> ---
> arch/s390/include/asm/uv.h | 59 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 59 insertions(+)
>
> diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
> index 1b97230a57ba..e1cef772fde1 100644
> --- a/arch/s390/include/asm/uv.h
> +++ b/arch/s390/include/asm/uv.h
> @@ -14,6 +14,7 @@
> #include <linux/types.h>
> #include <linux/errno.h>
> #include <linux/bug.h>
> +#include <linux/sched.h>
> #include <asm/page.h>
> #include <asm/gmap.h>
>
> @@ -91,6 +92,19 @@ struct uv_cb_cfs {
> u64 paddr;
> } __packed __aligned(8);
>
> +/*
> + * A common UV call struct for calls that take no payload
> + * Examples:
> + * Destroy cpu/config
> + * Verify
> + */
> +struct uv_cb_nodata {
> + struct uv_cb_header header;
> + u64 reserved08[2];
> + u64 handle;
> + u64 reserved20[4];
> +} __packed __aligned(8);
> +
> struct uv_cb_share {
> struct uv_cb_header header;
> u64 reserved08[3];
> @@ -98,6 +112,31 @@ struct uv_cb_share {
> u64 reserved28;
> } __packed __aligned(8);
>
> +/*
> + * Low level uv_call that takes r1 and r2 as parameter and avoids
> + * stalls for long running busy conditions by doing schedule
> + */
> +static inline int uv_call_sched(unsigned long r1, unsigned long r2)
> +{
> + int cc;
> +
> + do {
> + asm volatile(
> + "0: .insn rrf,0xB9A40000,%[r1],%[r2],0,0\n"
label not necessary
> + " ipm %[cc]\n"
> + " srl %[cc],28\n"
> + : [cc] "=d" (cc)
> + : [r1] "d" (r1), [r2] "d" (r2)
> + : "memory", "cc");
I was wondering if we could reuse uv_call() - something like
static inline int __uv_call(unsigned long r1, unsigned long r2)
{
int cc;
asm volatile(
" .insn rrf,0xB9A40000,%[r1],%[r2],0,0\n"
" ipm %[cc]\n"
" srl %[cc],28\n"
: [cc] "=d" (cc)
: [r1] "a" (r1), [r2] "a" (r2)
: "memory", "cc");
return cc;
}
static inline int uv_call(unsigned long r1, unsigned long r2)
{
int rc;
do {
cc = __uv_call(unsigned long r1, unsigned long r2);
} while (cc > 1)
return rc;
}
static inline int uv_call_sched(unsigned long r1, unsigned long r2)
{
int rc;
do {
cc = __uv_call(unsigned long r1, unsigned long r2);
cond_resched();
} while (rc > 1)
return rc;
}
> + if (need_resched())
> + schedule();
cond_resched();
> + } while (cc > 1);
> + return cc;
> +}
> +
> +/*
> + * Low level uv_call that takes r1 and r2 as parameter
> + */
This "r1 and r2" does not sound like relevant news. Same for the other
variant above.
> static inline int uv_call(unsigned long r1, unsigned long r2)
> {
> int cc;
> @@ -113,6 +152,26 @@ static inline int uv_call(unsigned long r1, unsigned long r2)
> return cc;
> }
>
> +/*
> + * special variant of uv_call that only transports the cpu or guest
> + * handle and the command, like destroy or verify.
> + */
> +static inline int uv_cmd_nodata(u64 handle, u16 cmd, u32 *ret)
uv_call_sched_simple() ?
> +{
> + int rc;
> + struct uv_cb_nodata uvcb = {
> + .header.cmd = cmd,
> + .header.len = sizeof(uvcb),
> + .handle = handle,
> + };
> +
> + WARN(!handle, "No handle provided to Ultravisor call cmd %x\n", cmd);
> + rc = uv_call_sched(0, (u64)&uvcb);
> + if (ret)
> + *ret = *(u32 *)&uvcb.header.rc;
> + return rc ? -EINVAL : 0;
> +}
> +
> struct uv_info {
> unsigned long inst_calls_list[4];
> unsigned long uv_base_stor_len;
>
--
Thanks,
David / dhildenb
