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Commit c19805f8 authored by Christian Borntraeger's avatar Christian Borntraeger Committed by Martin Schwidefsky
Browse files

s390/cpumf: Use configuration level indication for sampling data 



Newer hardware provides the level of virtualization that a particular
sample belongs to. Use that information and fall back to the old
heuristics if the sample does not contain that information.

Reviewed-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: default avatarHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent b4623d4e

arch/s390/include/asm/cpu_mf.h

+2 −1
Original line number Diff line number Diff line
@@ -104,7 +104,8 @@ struct hws_basic_entry { 
	unsigned int P:1;	    /* 28 PSW Problem state		 */

	unsigned int AS:2;	    /* 29-30 PSW address-space control	 */

	unsigned int I:1;	    /* 31 entry valid or invalid	 */

	unsigned int:16;

	unsigned int CL:2;	    /* 32-33 Configuration Level	 */

	unsigned int:14;

	unsigned int prim_asn:16;   /* primary ASN			 */

	unsigned long long ia;	    /* Instruction Address		 */

	unsigned long long gpp;     /* Guest Program Parameter		 */

arch/s390/kernel/perf_cpum_sf.c

+20 −7
Original line number Diff line number Diff line
@@ -1002,16 +1002,29 @@ static int perf_push_sample(struct perf_event *event, struct sf_raw_sample *sfr) 
	psw_bits(regs.psw).as = sfr->basic.AS;



	/*

	 * A non-zero guest program parameter indicates a guest

	 * sample.

	 * Note that some early samples or samples from guests without

	 * Use the hardware provided configuration level to decide if the

	 * sample belongs to a guest or host. If that is not available,

	 * fall back to the following heuristics:

	 * A non-zero guest program parameter always indicates a guest

	 * sample. Some early samples or samples from guests without

	 * lpp usage would be misaccounted to the host. We use the asn

	 * value as a heuristic to detect most of these guest samples.

	 * If the value differs from the host hpp value, we assume

	 * it to be a KVM guest.

	 * value as an addon heuristic to detect most of these guest samples.

	 * If the value differs from the host hpp value, we assume to be a

	 * KVM guest.

	 */

	if (sfr->basic.gpp || sfr->basic.prim_asn != (u16) sfr->basic.hpp)

	switch (sfr->basic.CL) {

	case 1: /* logical partition */

		sde_regs->in_guest = 0;

		break;

	case 2: /* virtual machine */

		sde_regs->in_guest = 1;

		break;

	default: /* old machine, use heuristics */

		if (sfr->basic.gpp ||

		    sfr->basic.prim_asn != (u16)sfr->basic.hpp)

			sde_regs->in_guest = 1;

		break;

	}



	overflow = 0;

	if (perf_exclude_event(event, &regs, sde_regs))