Merge tag 'kvm-s390-next-4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: Features and fixes for 4.8 part1

Four bigger things:
1. The implementation of the STHYI opcode in the kernel. This is used
   in libraries like qclib [1] to provide enough information for a
   capacity and usage based software licence pricing. The STHYI content
   is defined by the related z/VM documentation [2]. Its data can be
   composed by accessing several other interfaces provided by LPAR or
   the machine. This information is partially sensitive or root-only
   so the kernel does the necessary filtering.
2. Preparation for nested virtualization (VSIE). KVM should query the
   proper sclp interfaces for the availability of some features before
   using it. In the past we have been sloppy and simply assumed that
   several features are available. With this we should be able to handle
   most cases of a missing feature.
3. CPU model interfaces extended by some additional features that are
   not covered by a facility bit in STFLE. For example all the crypto
   instructions of the coprocessor provide a query function. As reality
   tends to be more complex (e.g. export regulations might block some
   algorithms) we have to provide additional interfaces to query or
   set these non-stfle features.
4. Several fixes and changes detected and fixed when doing 1-3.

All features change base s390 code. All relevant patches have an ACK
from the s390 or component maintainers.

The next pull request for 4.8 (part2) will contain the implementation
of VSIE.

[1] http://www.ibm.com/developerworks/linux/linux390/qclib.html
[2] https://www.ibm.com/support/knowledgecenter/SSB27U_6.3.0/com.ibm.zvm.v630.hcpb4/hcpb4sth.htm

1 files changed, 471 insertions, 0 deletions

diff --git a/arch/s390/kvm/sthyi.c b/arch/s390/kvm/sthyi.c
new file mode 100644
index 0000000..bd98b7d
--- /dev/null
+++ b/arch/s390/kvm/sthyi.c
@@ -0,0 +1,471 @@
+/*
+ * store hypervisor information instruction emulation functions.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ *
+ * Copyright IBM Corp. 2016
+ * Author(s): Janosch Frank <frankja@linux.vnet.ibm.com>
+ */
+#include <linux/kvm_host.h>
+#include <linux/errno.h>
+#include <linux/pagemap.h>
+#include <linux/vmalloc.h>
+#include <linux/ratelimit.h>
+
+#include <asm/kvm_host.h>
+#include <asm/asm-offsets.h>
+#include <asm/sclp.h>
+#include <asm/diag.h>
+#include <asm/sysinfo.h>
+#include <asm/ebcdic.h>
+
+#include "kvm-s390.h"
+#include "gaccess.h"
+#include "trace.h"
+
+#define DED_WEIGHT 0xffff
+/*
+ * CP and IFL as EBCDIC strings, SP/0x40 determines the end of string
+ * as they are justified with spaces.
+ */
+#define CP  0xc3d7404040404040UL
+#define IFL 0xc9c6d34040404040UL
+
+enum hdr_flags {
+	HDR_NOT_LPAR   = 0x10,
+	HDR_STACK_INCM = 0x20,
+	HDR_STSI_UNAV  = 0x40,
+	HDR_PERF_UNAV  = 0x80,
+};
+
+enum mac_validity {
+	MAC_NAME_VLD = 0x20,
+	MAC_ID_VLD   = 0x40,
+	MAC_CNT_VLD  = 0x80,
+};
+
+enum par_flag {
+	PAR_MT_EN = 0x80,
+};
+
+enum par_validity {
+	PAR_GRP_VLD  = 0x08,
+	PAR_ID_VLD   = 0x10,
+	PAR_ABS_VLD  = 0x20,
+	PAR_WGHT_VLD = 0x40,
+	PAR_PCNT_VLD  = 0x80,
+};
+
+struct hdr_sctn {
+	u8 infhflg1;
+	u8 infhflg2; /* reserved */
+	u8 infhval1; /* reserved */
+	u8 infhval2; /* reserved */
+	u8 reserved[3];
+	u8 infhygct;
+	u16 infhtotl;
+	u16 infhdln;
+	u16 infmoff;
+	u16 infmlen;
+	u16 infpoff;
+	u16 infplen;
+	u16 infhoff1;
+	u16 infhlen1;
+	u16 infgoff1;
+	u16 infglen1;
+	u16 infhoff2;
+	u16 infhlen2;
+	u16 infgoff2;
+	u16 infglen2;
+	u16 infhoff3;
+	u16 infhlen3;
+	u16 infgoff3;
+	u16 infglen3;
+	u8 reserved2[4];
+} __packed;
+
+struct mac_sctn {
+	u8 infmflg1; /* reserved */
+	u8 infmflg2; /* reserved */
+	u8 infmval1;
+	u8 infmval2; /* reserved */
+	u16 infmscps;
+	u16 infmdcps;
+	u16 infmsifl;
+	u16 infmdifl;
+	char infmname[8];
+	char infmtype[4];
+	char infmmanu[16];
+	char infmseq[16];
+	char infmpman[4];
+	u8 reserved[4];
+} __packed;
+
+struct par_sctn {
+	u8 infpflg1;
+	u8 infpflg2; /* reserved */
+	u8 infpval1;
+	u8 infpval2; /* reserved */
+	u16 infppnum;
+	u16 infpscps;
+	u16 infpdcps;
+	u16 infpsifl;
+	u16 infpdifl;
+	u16 reserved;
+	char infppnam[8];
+	u32 infpwbcp;
+	u32 infpabcp;
+	u32 infpwbif;
+	u32 infpabif;
+	char infplgnm[8];
+	u32 infplgcp;
+	u32 infplgif;
+} __packed;
+
+struct sthyi_sctns {
+	struct hdr_sctn hdr;
+	struct mac_sctn mac;
+	struct par_sctn par;
+} __packed;
+
+struct cpu_inf {
+	u64 lpar_cap;
+	u64 lpar_grp_cap;
+	u64 lpar_weight;
+	u64 all_weight;
+	int cpu_num_ded;
+	int cpu_num_shd;
+};
+
+struct lpar_cpu_inf {
+	struct cpu_inf cp;
+	struct cpu_inf ifl;
+};
+
+static inline u64 cpu_id(u8 ctidx, void *diag224_buf)
+{
+	return *((u64 *)(diag224_buf + (ctidx + 1) * DIAG204_CPU_NAME_LEN));
+}
+
+/*
+ * Scales the cpu capping from the lpar range to the one expected in
+ * sthyi data.
+ *
+ * diag204 reports a cap in hundredths of processor units.
+ * z/VM's range for one core is 0 - 0x10000.
+ */
+static u32 scale_cap(u32 in)
+{
+	return (0x10000 * in) / 100;
+}
+
+static void fill_hdr(struct sthyi_sctns *sctns)
+{
+	sctns->hdr.infhdln = sizeof(sctns->hdr);
+	sctns->hdr.infmoff = sizeof(sctns->hdr);
+	sctns->hdr.infmlen = sizeof(sctns->mac);
+	sctns->hdr.infplen = sizeof(sctns->par);
+	sctns->hdr.infpoff = sctns->hdr.infhdln + sctns->hdr.infmlen;
+	sctns->hdr.infhtotl = sctns->hdr.infpoff + sctns->hdr.infplen;
+}
+
+static void fill_stsi_mac(struct sthyi_sctns *sctns,
+			  struct sysinfo_1_1_1 *sysinfo)
+{
+	if (stsi(sysinfo, 1, 1, 1))
+		return;
+
+	sclp_ocf_cpc_name_copy(sctns->mac.infmname);
+
+	memcpy(sctns->mac.infmtype, sysinfo->type, sizeof(sctns->mac.infmtype));
+	memcpy(sctns->mac.infmmanu, sysinfo->manufacturer, sizeof(sctns->mac.infmmanu));
+	memcpy(sctns->mac.infmpman, sysinfo->plant, sizeof(sctns->mac.infmpman));
+	memcpy(sctns->mac.infmseq, sysinfo->sequence, sizeof(sctns->mac.infmseq));
+
+	sctns->mac.infmval1 |= MAC_ID_VLD | MAC_NAME_VLD;
+}
+
+static void fill_stsi_par(struct sthyi_sctns *sctns,
+			  struct sysinfo_2_2_2 *sysinfo)
+{
+	if (stsi(sysinfo, 2, 2, 2))
+		return;
+
+	sctns->par.infppnum = sysinfo->lpar_number;
+	memcpy(sctns->par.infppnam, sysinfo->name, sizeof(sctns->par.infppnam));
+
+	sctns->par.infpval1 |= PAR_ID_VLD;
+}
+
+static void fill_stsi(struct sthyi_sctns *sctns)
+{
+	void *sysinfo;
+
+	/* Errors are handled through the validity bits in the response. */
+	sysinfo = (void *)__get_free_page(GFP_KERNEL);
+	if (!sysinfo)
+		return;
+
+	fill_stsi_mac(sctns, sysinfo);
+	fill_stsi_par(sctns, sysinfo);
+
+	free_pages((unsigned long)sysinfo, 0);
+}
+
+static void fill_diag_mac(struct sthyi_sctns *sctns,
+			  struct diag204_x_phys_block *block,
+			  void *diag224_buf)
+{
+	int i;
+
+	for (i = 0; i < block->hdr.cpus; i++) {
+		switch (cpu_id(block->cpus[i].ctidx, diag224_buf)) {
+		case CP:
+			if (block->cpus[i].weight == DED_WEIGHT)
+				sctns->mac.infmdcps++;
+			else
+				sctns->mac.infmscps++;
+			break;
+		case IFL:
+			if (block->cpus[i].weight == DED_WEIGHT)
+				sctns->mac.infmdifl++;
+			else
+				sctns->mac.infmsifl++;
+			break;
+		}
+	}
+	sctns->mac.infmval1 |= MAC_CNT_VLD;
+}
+
+/* Returns a pointer to the the next partition block. */
+static struct diag204_x_part_block *lpar_cpu_inf(struct lpar_cpu_inf *part_inf,
+						 bool this_lpar,
+						 void *diag224_buf,
+						 struct diag204_x_part_block *block)
+{
+	int i, capped = 0, weight_cp = 0, weight_ifl = 0;
+	struct cpu_inf *cpu_inf;
+
+	for (i = 0; i < block->hdr.rcpus; i++) {
+		if (!(block->cpus[i].cflag & DIAG204_CPU_ONLINE))
+			continue;
+
+		switch (cpu_id(block->cpus[i].ctidx, diag224_buf)) {
+		case CP:
+			cpu_inf = &part_inf->cp;
+			if (block->cpus[i].cur_weight < DED_WEIGHT)
+				weight_cp |= block->cpus[i].cur_weight;
+			break;
+		case IFL:
+			cpu_inf = &part_inf->ifl;
+			if (block->cpus[i].cur_weight < DED_WEIGHT)
+				weight_ifl |= block->cpus[i].cur_weight;
+			break;
+		default:
+			continue;
+		}
+
+		if (!this_lpar)
+			continue;
+
+		capped |= block->cpus[i].cflag & DIAG204_CPU_CAPPED;
+		cpu_inf->lpar_cap |= block->cpus[i].cpu_type_cap;
+		cpu_inf->lpar_grp_cap |= block->cpus[i].group_cpu_type_cap;
+
+		if (block->cpus[i].weight == DED_WEIGHT)
+			cpu_inf->cpu_num_ded += 1;
+		else
+			cpu_inf->cpu_num_shd += 1;
+	}
+
+	if (this_lpar && capped) {
+		part_inf->cp.lpar_weight = weight_cp;
+		part_inf->ifl.lpar_weight = weight_ifl;
+	}
+	part_inf->cp.all_weight += weight_cp;
+	part_inf->ifl.all_weight += weight_ifl;
+	return (struct diag204_x_part_block *)&block->cpus[i];
+}
+
+static void fill_diag(struct sthyi_sctns *sctns)
+{
+	int i, r, pages;
+	bool this_lpar;
+	void *diag204_buf;
+	void *diag224_buf = NULL;
+	struct diag204_x_info_blk_hdr *ti_hdr;
+	struct diag204_x_part_block *part_block;
+	struct diag204_x_phys_block *phys_block;
+	struct lpar_cpu_inf lpar_inf = {};
+
+	/* Errors are handled through the validity bits in the response. */
+	pages = diag204((unsigned long)DIAG204_SUBC_RSI |
+			(unsigned long)DIAG204_INFO_EXT, 0, NULL);
+	if (pages <= 0)
+		return;
+
+	diag204_buf = vmalloc(PAGE_SIZE * pages);
+	if (!diag204_buf)
+		return;
+
+	r = diag204((unsigned long)DIAG204_SUBC_STIB7 |
+		    (unsigned long)DIAG204_INFO_EXT, pages, diag204_buf);
+	if (r < 0)
+		goto out;
+
+	diag224_buf = kmalloc(PAGE_SIZE, GFP_KERNEL | GFP_DMA);
+	if (!diag224_buf || diag224(diag224_buf))
+		goto out;
+
+	ti_hdr = diag204_buf;
+	part_block = diag204_buf + sizeof(*ti_hdr);
+
+	for (i = 0; i < ti_hdr->npar; i++) {
+		/*
+		 * For the calling lpar we also need to get the cpu
+		 * caps and weights. The time information block header
+		 * specifies the offset to the partition block of the
+		 * caller lpar, so we know when we process its data.
+		 */
+		this_lpar = (void *)part_block - diag204_buf == ti_hdr->this_part;
+		part_block = lpar_cpu_inf(&lpar_inf, this_lpar, diag224_buf,
+					  part_block);
+	}
+
+	phys_block = (struct diag204_x_phys_block *)part_block;
+	part_block = diag204_buf + ti_hdr->this_part;
+	if (part_block->hdr.mtid)
+		sctns->par.infpflg1 = PAR_MT_EN;
+
+	sctns->par.infpval1 |= PAR_GRP_VLD;
+	sctns->par.infplgcp = scale_cap(lpar_inf.cp.lpar_grp_cap);
+	sctns->par.infplgif = scale_cap(lpar_inf.ifl.lpar_grp_cap);
+	memcpy(sctns->par.infplgnm, part_block->hdr.hardware_group_name,
+	       sizeof(sctns->par.infplgnm));
+
+	sctns->par.infpscps = lpar_inf.cp.cpu_num_shd;
+	sctns->par.infpdcps = lpar_inf.cp.cpu_num_ded;
+	sctns->par.infpsifl = lpar_inf.ifl.cpu_num_shd;
+	sctns->par.infpdifl = lpar_inf.ifl.cpu_num_ded;
+	sctns->par.infpval1 |= PAR_PCNT_VLD;
+
+	sctns->par.infpabcp = scale_cap(lpar_inf.cp.lpar_cap);
+	sctns->par.infpabif = scale_cap(lpar_inf.ifl.lpar_cap);
+	sctns->par.infpval1 |= PAR_ABS_VLD;
+
+	/*
+	 * Everything below needs global performance data to be
+	 * meaningful.
+	 */
+	if (!(ti_hdr->flags & DIAG204_LPAR_PHYS_FLG)) {
+		sctns->hdr.infhflg1 |= HDR_PERF_UNAV;
+		goto out;
+	}
+
+	fill_diag_mac(sctns, phys_block, diag224_buf);
+
+	if (lpar_inf.cp.lpar_weight) {
+		sctns->par.infpwbcp = sctns->mac.infmscps * 0x10000 *
+			lpar_inf.cp.lpar_weight / lpar_inf.cp.all_weight;
+	}
+
+	if (lpar_inf.ifl.lpar_weight) {
+		sctns->par.infpwbif = sctns->mac.infmsifl * 0x10000 *
+			lpar_inf.ifl.lpar_weight / lpar_inf.ifl.all_weight;
+	}
+	sctns->par.infpval1 |= PAR_WGHT_VLD;
+
+out:
+	kfree(diag224_buf);
+	vfree(diag204_buf);
+}
+
+static int sthyi(u64 vaddr)
+{
+	register u64 code asm("0") = 0;
+	register u64 addr asm("2") = vaddr;
+	int cc;
+
+	asm volatile(
+		".insn   rre,0xB2560000,%[code],%[addr]\n"
+		"ipm     %[cc]\n"
+		"srl     %[cc],28\n"
+		: [cc] "=d" (cc)
+		: [code] "d" (code), [addr] "a" (addr)
+		: "memory", "cc");
+	return cc;
+}
+
+int handle_sthyi(struct kvm_vcpu *vcpu)
+{
+	int reg1, reg2, r = 0;
+	u64 code, addr, cc = 0;
+	struct sthyi_sctns *sctns = NULL;
+
+	/*
+	 * STHYI requires extensive locking in the higher hypervisors
+	 * and is very computational/memory expensive. Therefore we
+	 * ratelimit the executions per VM.
+	 */
+	if (!__ratelimit(&vcpu->kvm->arch.sthyi_limit)) {
+		kvm_s390_retry_instr(vcpu);
+		return 0;
+	}
+
+	kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
+	code = vcpu->run->s.regs.gprs[reg1];
+	addr = vcpu->run->s.regs.gprs[reg2];
+
+	vcpu->stat.instruction_sthyi++;
+	VCPU_EVENT(vcpu, 3, "STHYI: fc: %llu addr: 0x%016llx", code, addr);
+	trace_kvm_s390_handle_sthyi(vcpu, code, addr);
+
+	if (reg1 == reg2 || reg1 & 1 || reg2 & 1 || addr & ~PAGE_MASK)
+		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+
+	if (code & 0xffff) {
+		cc = 3;
+		goto out;
+	}
+
+	/*
+	 * If the page has not yet been faulted in, we want to do that
+	 * now and not after all the expensive calculations.
+	 */
+	r = write_guest(vcpu, addr, reg2, &cc, 1);
+	if (r)
+		return kvm_s390_inject_prog_cond(vcpu, r);
+
+	sctns = (void *)get_zeroed_page(GFP_KERNEL);
+	if (!sctns)
+		return -ENOMEM;
+
+	/*
+	 * If we are a guest, we don't want to emulate an emulated
+	 * instruction. We ask the hypervisor to provide the data.
+	 */
+	if (test_facility(74)) {
+		cc = sthyi((u64)sctns);
+		goto out;
+	}
+
+	fill_hdr(sctns);
+	fill_stsi(sctns);
+	fill_diag(sctns);
+
+out:
+	if (!cc) {
+		r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);
+		if (r) {
+			free_page((unsigned long)sctns);
+			return kvm_s390_inject_prog_cond(vcpu, r);
+		}
+	}
+
+	free_page((unsigned long)sctns);
+	vcpu->run->s.regs.gprs[reg2 + 1] = cc ? 4 : 0;
+	kvm_s390_set_psw_cc(vcpu, cc);
+	return r;
+}