[kvm-unit-tests v3 08/13] powerpc/spapr_vpa: Add basic VPA tests

Nicholas Piggin
2023-03-27T12:46:09Z

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.]
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
Since v2:
- Added to unittests.cfg [Thomas review]
- Removed __always_inline header hunk [Thomas review]
- Updated comments [Thomas review]
- Better coverage of VPA registration error cases [Thomas review]
- Fix unbalanced prefix push [Thomas review]
- Don't print VPA contents unless -v option is given.
- Split VPA hcall register/unregister tests from testing of elements
of the VPA when it has been registered into different functions and
prefixes.

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 1173fea..e0f5009 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 0000000..11dde01
--- /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 ea68447..b0ed2b1 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 0000000..5586eb8
--- /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 e206a22..dd5f361 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
--
2.37.2