Subject: [kvm-unit-tests v4 07/12] powerpc/spapr_vpa: Add basic VPA tests

From: Nicholas Piggin <[email-masked]>
Date: Thu, 8 Jun 2023 17:58:21 +1000

The VPA is an optional memory structure shared between the hypervisor
and operating system, defined by PAPR. This test defines the structure
and adds registration, deregistration, and a few simple sanity tests.

[Thanks to Thomas Huth for suggesting many of the test cases.]

Reviewed-by: Thomas Huth <[email-masked]>
Signed-off-by: Nicholas Piggin <[email-masked]>
---
 lib/powerpc/asm/hcall.h |   1 +
 lib/ppc64/asm/vpa.h     |  62 +++++++++++++++
 powerpc/Makefile.ppc64  |   2 +-
 powerpc/spapr_vpa.c     | 172 ++++++++++++++++++++++++++++++++++++++++
 powerpc/unittests.cfg   |   3 +
 5 files changed, 239 insertions(+), 1 deletion(-)
 create mode 100644 lib/ppc64/asm/vpa.h
 create mode 100644 powerpc/spapr_vpa.c

diff --git a/lib/powerpc/asm/hcall.h b/lib/powerpc/asm/hcall.h
index 1173feaa..e0f5009e 100644
--- a/lib/powerpc/asm/hcall.h
+++ b/lib/powerpc/asm/hcall.h
@@ -18,6 +18,7 @@
 #define H_SET_SPRG0		0x24
 #define H_SET_DABR		0x28
 #define H_PAGE_INIT		0x2c
+#define H_REGISTER_VPA		0xDC
 #define H_CEDE			0xE0
 #define H_GET_TERM_CHAR		0x54
 #define H_PUT_TERM_CHAR		0x58
diff --git a/lib/ppc64/asm/vpa.h b/lib/ppc64/asm/vpa.h
new file mode 100644
index 00000000..11dde018
--- /dev/null
+++ b/lib/ppc64/asm/vpa.h
@@ -0,0 +1,62 @@
+#ifndef _ASMPOWERPC_VPA_H_
+#define _ASMPOWERPC_VPA_H_
+/*
+ * This work is licensed under the terms of the GNU LGPL, version 2.
+ */
+
+#ifndef __ASSEMBLY__
+
+struct vpa {
+	uint32_t	descriptor;
+	uint16_t	size;
+	uint8_t		reserved1[3];
+	uint8_t		status;
+	uint8_t		reserved2[14];
+	uint32_t	fru_node_id;
+	uint32_t	fru_proc_id;
+	uint8_t		reserved3[56];
+	uint8_t		vhpn_change_counters[8];
+	uint8_t		reserved4[80];
+	uint8_t		cede_latency;
+	uint8_t		maintain_ebb;
+	uint8_t		reserved5[6];
+	uint8_t		dtl_enable_mask;
+	uint8_t		dedicated_cpu_donate;
+	uint8_t		maintain_fpr;
+	uint8_t		maintain_pmc;
+	uint8_t		reserved6[28];
+	uint64_t	idle_estimate_purr;
+	uint8_t		reserved7[28];
+	uint16_t	maintain_nr_slb;
+	uint8_t		idle;
+	uint8_t		maintain_vmx;
+	uint32_t	vp_dispatch_count;
+	uint32_t	vp_dispatch_dispersion;
+	uint64_t	vp_fault_count;
+	uint64_t	vp_fault_tb;
+	uint64_t	purr_exprop_idle;
+	uint64_t	spurr_exprop_idle;
+	uint64_t	purr_exprop_busy;
+	uint64_t	spurr_exprop_busy;
+	uint64_t	purr_donate_idle;
+	uint64_t	spurr_donate_idle;
+	uint64_t	purr_donate_busy;
+	uint64_t	spurr_donate_busy;
+	uint64_t	vp_wait3_tb;
+	uint64_t	vp_wait2_tb;
+	uint64_t	vp_wait1_tb;
+	uint64_t	purr_exprop_adjunct_busy;
+	uint64_t	spurr_exprop_adjunct_busy;
+	uint32_t	supervisor_pagein_count;
+	uint8_t		reserved8[4];
+	uint64_t	purr_exprop_adjunct_idle;
+	uint64_t	spurr_exprop_adjunct_idle;
+	uint64_t	adjunct_insns_executed;
+	uint8_t		reserved9[120];
+	uint64_t	dtl_index;
+	uint8_t		reserved10[96];
+};
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASMPOWERPC_VPA_H_ */
diff --git a/powerpc/Makefile.ppc64 b/powerpc/Makefile.ppc64
index ea684470..b0ed2b10 100644
--- a/powerpc/Makefile.ppc64
+++ b/powerpc/Makefile.ppc64
@@ -19,7 +19,7 @@ reloc.o  = $(TEST_DIR)/reloc64.o
 OBJDIRS += lib/ppc64
 
 # ppc64 specific tests
-tests =
+tests = $(TEST_DIR)/spapr_vpa.elf
 
 include $(SRCDIR)/$(TEST_DIR)/Makefile.common
 
diff --git a/powerpc/spapr_vpa.c b/powerpc/spapr_vpa.c
new file mode 100644
index 00000000..5586eb8d
--- /dev/null
+++ b/powerpc/spapr_vpa.c
@@ -0,0 +1,172 @@
+/*
+ * Test sPAPR "Per Virtual Processor Area" and H_REGISTER_VPA hypervisor call
+ * (also known as VPA, also known as lppaca in the Linux pseries kernel).
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.
+ */
+#include <libcflat.h>
+#include <libfdt/libfdt.h>
+#include <devicetree.h>
+#include <util.h>
+#include <alloc.h>
+#include <asm/processor.h>
+#include <asm/setup.h>
+#include <asm/hcall.h>
+#include <asm/vpa.h>
+#include <asm/io.h> /* for endian accessors */
+
+static int verbose;
+
+static void print_vpa(struct vpa *vpa)
+{
+	printf("VPA\n");
+	printf("descriptor:			0x%08x\n", be32_to_cpu(vpa->descriptor));
+	printf("size:				    0x%04x\n", be16_to_cpu(vpa->size));
+	printf("status:				      0x%02x\n", vpa->status);
+	printf("fru_node_id:			0x%08x\n", be32_to_cpu(vpa->fru_node_id));
+	printf("fru_proc_id:			0x%08x\n", be32_to_cpu(vpa->fru_proc_id));
+	printf("vhpn_change_counters:		0x%02x %02x %02x %02x %02x %02x %02x %02x\n", vpa->vhpn_change_counters[0], vpa->vhpn_change_counters[1], vpa->vhpn_change_counters[2], vpa->vhpn_change_counters[3], vpa->vhpn_change_counters[4], vpa->vhpn_change_counters[5], vpa->vhpn_change_counters[6], vpa->vhpn_change_counters[7]);
+	printf("vp_dispatch_count:		0x%08x\n", be32_to_cpu(vpa->vp_dispatch_count));
+	printf("vp_dispatch_dispersion:		0x%08x\n", be32_to_cpu(vpa->vp_dispatch_dispersion));
+	printf("vp_fault_count:			0x%08lx\n", be64_to_cpu(vpa->vp_fault_count));
+	printf("vp_fault_tb:			0x%08lx\n", be64_to_cpu(vpa->vp_fault_tb));
+	printf("purr_exprop_idle:		0x%08lx\n", be64_to_cpu(vpa->purr_exprop_idle));
+	printf("spurr_exprop_idle:		0x%08lx\n", be64_to_cpu(vpa->spurr_exprop_idle));
+	printf("purr_exprop_busy:		0x%08lx\n", be64_to_cpu(vpa->purr_exprop_busy));
+	printf("spurr_exprop_busy:		0x%08lx\n", be64_to_cpu(vpa->spurr_exprop_busy));
+	printf("purr_donate_idle:		0x%08lx\n", be64_to_cpu(vpa->purr_donate_idle));
+	printf("spurr_donate_idle:		0x%08lx\n", be64_to_cpu(vpa->spurr_donate_idle));
+	printf("purr_donate_busy:		0x%08lx\n", be64_to_cpu(vpa->purr_donate_busy));
+	printf("spurr_donate_busy:		0x%08lx\n", be64_to_cpu(vpa->spurr_donate_busy));
+	printf("vp_wait3_tb:			0x%08lx\n", be64_to_cpu(vpa->vp_wait3_tb));
+	printf("vp_wait2_tb:			0x%08lx\n", be64_to_cpu(vpa->vp_wait2_tb));
+	printf("vp_wait1_tb:			0x%08lx\n", be64_to_cpu(vpa->vp_wait1_tb));
+	printf("purr_exprop_adjunct_busy:	0x%08lx\n", be64_to_cpu(vpa->purr_exprop_adjunct_busy));
+	printf("spurr_exprop_adjunct_busy:	0x%08lx\n", be64_to_cpu(vpa->spurr_exprop_adjunct_busy));
+	printf("purr_exprop_adjunct_idle:	0x%08lx\n", be64_to_cpu(vpa->purr_exprop_adjunct_idle));
+	printf("spurr_exprop_adjunct_idle:	0x%08lx\n", be64_to_cpu(vpa->spurr_exprop_adjunct_idle));
+	printf("adjunct_insns_executed:		0x%08lx\n", be64_to_cpu(vpa->adjunct_insns_executed));
+	printf("dtl_index:			0x%08lx\n", be64_to_cpu(vpa->dtl_index));
+}
+
+#define SUBFUNC_RESERVED	(0ULL << 45)
+#define SUBFUNC_REGISTER	(1ULL << 45)
+#define SUBFUNC_DEREGISTER	(5ULL << 45)
+
+/**
+ * Test the H_REGISTER_VPA h-call register/deregister calls.
+ */
+static void test_register_vpa(void)
+{
+	struct vpa *vpa;
+	uint32_t cpuid = fdt_boot_cpuid_phys(dt_fdt());
+	int rc;
+
+	report_prefix_push("H_REGISTER_VPA");
+
+	vpa = memalign(4096, sizeof(*vpa));
+
+	memset(vpa, 0, sizeof(*vpa));
+
+	vpa->size = cpu_to_be16(sizeof(*vpa));
+
+	rc = hcall(H_REGISTER_VPA, SUBFUNC_RESERVED, cpuid, vpa);
+	report(rc == H_PARAMETER, "Reserved sub-function fails with H_PARAMETER");
+
+	rc = hcall(H_REGISTER_VPA, SUBFUNC_REGISTER, 0xbadbad, vpa);
+	report(rc == H_PARAMETER, "Register with invalid proc-no fails");
+
+	rc = hcall(H_REGISTER_VPA, SUBFUNC_REGISTER, cpuid, (void *)vpa + 8);
+	report(rc == H_PARAMETER, "Register with VPA not cacheline aligned fails");
+
+
+	rc = hcall(H_REGISTER_VPA, SUBFUNC_REGISTER, cpuid, (void *)vpa + 4096 - 128);
+	report(rc == H_PARAMETER, "Register with VPA spanning 4096 bytes fails");
+
+	vpa->size = cpu_to_be16(632);
+	rc = hcall(H_REGISTER_VPA, SUBFUNC_REGISTER, cpuid, (void *)vpa);
+	report(rc == H_PARAMETER, "Register with VPA size < 640 bytes fails");
+	vpa->size = cpu_to_be16(sizeof(*vpa));
+
+	rc = hcall(H_REGISTER_VPA, SUBFUNC_REGISTER, cpuid, PHYSICAL_END);
+	report(rc == H_PARAMETER, "Register with VPA outside guest real memory fails");
+
+
+	rc = hcall(H_REGISTER_VPA, SUBFUNC_REGISTER, cpuid, vpa);
+	report(rc == H_SUCCESS, "VPA registered");
+
+	rc = hcall(H_REGISTER_VPA, SUBFUNC_DEREGISTER, cpuid, NULL);
+	report(rc == H_SUCCESS, "VPA deregistered");
+
+	/*
+	 * From PAPR: "note no check is made that a valid VPA registration
+	 * exists".
+	 */
+	rc = hcall(H_REGISTER_VPA, SUBFUNC_DEREGISTER, cpuid, NULL);
+	report(rc == H_SUCCESS, "Deregister succeeds with no VPA registered");
+
+	rc = hcall(H_REGISTER_VPA, SUBFUNC_DEREGISTER, 0xbadbad, NULL);
+	report(rc == H_PARAMETER, "Deregister with invalid proc-no fails");
+
+	report_prefix_pop();
+}
+
+/**
+ * Test some VPA fields.
+ */
+static void test_vpa(void)
+{
+	struct vpa *vpa;
+	uint32_t cpuid = fdt_boot_cpuid_phys(dt_fdt());
+	int disp_count1, disp_count2;
+	int rc;
+
+	report_prefix_push("VPA");
+
+	vpa = memalign(4096, sizeof(*vpa));
+
+	memset(vpa, 0, sizeof(*vpa));
+
+	vpa->size = cpu_to_be16(sizeof(*vpa));
+
+	rc = hcall(H_REGISTER_VPA, SUBFUNC_REGISTER, cpuid, vpa);
+	if (rc != H_SUCCESS) {
+		report_skip("VPA could not be registered");
+		return;
+	}
+
+	if (verbose)
+		print_vpa(vpa);
+
+	disp_count1 = be32_to_cpu(vpa->vp_dispatch_count);
+	report(disp_count1 % 2 == 0, "Dispatch count is even while running");
+	msleep(100);
+	disp_count2 = be32_to_cpu(vpa->vp_dispatch_count);
+	report(disp_count1 != disp_count2, "Dispatch count increments over H_CEDE");
+
+	rc = hcall(H_REGISTER_VPA, SUBFUNC_DEREGISTER, cpuid, vpa);
+	if (rc != H_SUCCESS)
+		report_fail("Could not deregister after registration");
+
+	disp_count1 = be32_to_cpu(vpa->vp_dispatch_count);
+	report(disp_count1 % 2 == 1, "Dispatch count is odd after deregister");
+
+	report_prefix_pop();
+}
+
+int main(int argc, char *argv[])
+{
+	int i;
+
+	for (i = 1; i < argc; i++) {
+		if (strcmp(argv[i], "-v") == 0) {
+			verbose = 1;
+		}
+	}
+
+	test_register_vpa();
+
+	test_vpa();
+
+	return report_summary();
+}
diff --git a/powerpc/unittests.cfg b/powerpc/unittests.cfg
index e206a225..dd5f361c 100644
--- a/powerpc/unittests.cfg
+++ b/powerpc/unittests.cfg
@@ -39,6 +39,9 @@ groups = selftest
 [spapr_hcall]
 file = spapr_hcall.elf
 
+[spapr_vpa]
+file = spapr_vpa.elf
+
 [rtas-get-time-of-day]
 file = rtas.elf
 timeout = 5
-- 
2.40.1