[PATCH v3 12/13] KVM: selftests: x86: Check that the palette table exists before using it

From: Mingwei Zhang
Date: Tue Feb 21 2023 - 11:38:30 EST


From: Aaron Lewis <aaronlewis@xxxxxxxxxx>

Check that the palette table exists before using it. The maximum number of
AMX palette tables is enumerated by CPUID.1DH:EAX. Assert that the palette
used in amx_test, CPUID.1DH.1H, does not exceed that maximum.

Signed-off-by: Aaron Lewis <aaronlewis@xxxxxxxxxx>
Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx>
---
tools/testing/selftests/kvm/include/x86_64/processor.h | 1 +
tools/testing/selftests/kvm/x86_64/amx_test.c | 5 +++++
2 files changed, 6 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 5cfd7ef40d78..a6a86c41ed75 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -223,6 +223,7 @@ struct kvm_x86_cpu_property {
#define X86_PROPERTY_XSTATE_MAX_SIZE KVM_X86_CPU_PROPERTY(0xd, 0, ECX, 0, 31)
#define X86_PROPERTY_XSTATE_TILE_SIZE KVM_X86_CPU_PROPERTY(0xd, 18, EAX, 0, 31)
#define X86_PROPERTY_XSTATE_TILE_OFFSET KVM_X86_CPU_PROPERTY(0xd, 18, EBX, 0, 31)
+#define X86_PROPERTY_AMX_MAX_PALETTE_TABLES KVM_X86_CPU_PROPERTY(0x1d, 0, EAX, 0, 31)
#define X86_PROPERTY_AMX_TOTAL_TILE_BYTES KVM_X86_CPU_PROPERTY(0x1d, 1, EAX, 0, 15)
#define X86_PROPERTY_AMX_BYTES_PER_TILE KVM_X86_CPU_PROPERTY(0x1d, 1, EAX, 16, 31)
#define X86_PROPERTY_AMX_BYTES_PER_ROW KVM_X86_CPU_PROPERTY(0x1d, 1, EBX, 0, 15)
diff --git a/tools/testing/selftests/kvm/x86_64/amx_test.c b/tools/testing/selftests/kvm/x86_64/amx_test.c
index deacd21cf744..2fd6a8a928d9 100644
--- a/tools/testing/selftests/kvm/x86_64/amx_test.c
+++ b/tools/testing/selftests/kvm/x86_64/amx_test.c
@@ -30,6 +30,7 @@
#define XSAVE_SIZE ((NUM_TILES * TILE_SIZE) + PAGE_SIZE)

/* Tile configuration associated: */
+#define PALETTE_TABLE_INDEX 1
#define MAX_TILES 16
#define RESERVED_BYTES 14

@@ -120,6 +121,10 @@ static void check_xtile_info(void)
GUEST_ASSERT(xtile.xsave_size == 8192);
GUEST_ASSERT(sizeof(struct tile_data) >= xtile.xsave_size);

+ GUEST_ASSERT(this_cpu_has_p(X86_PROPERTY_AMX_MAX_PALETTE_TABLES));
+ GUEST_ASSERT(this_cpu_property(X86_PROPERTY_AMX_MAX_PALETTE_TABLES) >=
+ PALETTE_TABLE_INDEX);
+
GUEST_ASSERT(this_cpu_has_p(X86_PROPERTY_AMX_NR_TILE_REGS));
xtile.max_names = this_cpu_property(X86_PROPERTY_AMX_NR_TILE_REGS);
GUEST_ASSERT(xtile.max_names == 8);
--
2.39.2.637.g21b0678d19-goog