KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted

Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>

1 files changed, 82 insertions, 0 deletions

diff --git a/drivers/edac/mce_amd.h b/drivers/edac/mce_amd.h
new file mode 100644
index 000000000..4811b18d9
--- /dev/null
+++ b/drivers/edac/mce_amd.h
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _EDAC_MCE_AMD_H
+#define _EDAC_MCE_AMD_H
+
+#include <linux/notifier.h>
+
+#include <asm/mce.h>
+
+#define EC(x)				((x) & 0xffff)
+
+#define LOW_SYNDROME(x)			(((x) >> 15) & 0xff)
+#define HIGH_SYNDROME(x)		(((x) >> 24) & 0xff)
+
+#define TLB_ERROR(x)			(((x) & 0xFFF0) == 0x0010)
+#define MEM_ERROR(x)			(((x) & 0xFF00) == 0x0100)
+#define BUS_ERROR(x)			(((x) & 0xF800) == 0x0800)
+#define INT_ERROR(x)			(((x) & 0xF4FF) == 0x0400)
+
+#define TT(x)				(((x) >> 2) & 0x3)
+#define TT_MSG(x)			tt_msgs[TT(x)]
+#define II(x)				(((x) >> 2) & 0x3)
+#define II_MSG(x)			ii_msgs[II(x)]
+#define LL(x)				((x) & 0x3)
+#define LL_MSG(x)			ll_msgs[LL(x)]
+#define TO(x)				(((x) >> 8) & 0x1)
+#define TO_MSG(x)			to_msgs[TO(x)]
+#define PP(x)				(((x) >> 9) & 0x3)
+#define PP_MSG(x)			pp_msgs[PP(x)]
+#define UU(x)				(((x) >> 8) & 0x3)
+#define UU_MSG(x)			uu_msgs[UU(x)]
+
+#define R4(x)				(((x) >> 4) & 0xf)
+#define R4_MSG(x)			((R4(x) < 9) ?  rrrr_msgs[R4(x)] : "Wrong R4!")
+
+extern const char * const pp_msgs[];
+
+enum tt_ids {
+	TT_INSTR = 0,
+	TT_DATA,
+	TT_GEN,
+	TT_RESV,
+};
+
+enum ll_ids {
+	LL_RESV = 0,
+	LL_L1,
+	LL_L2,
+	LL_LG,
+};
+
+enum ii_ids {
+	II_MEM = 0,
+	II_RESV,
+	II_IO,
+	II_GEN,
+};
+
+enum rrrr_ids {
+	R4_GEN	= 0,
+	R4_RD,
+	R4_WR,
+	R4_DRD,
+	R4_DWR,
+	R4_IRD,
+	R4_PREF,
+	R4_EVICT,
+	R4_SNOOP,
+};
+
+/*
+ * per-family decoder ops
+ */
+struct amd_decoder_ops {
+	bool (*mc0_mce)(u16, u8);
+	bool (*mc1_mce)(u16, u8);
+	bool (*mc2_mce)(u16, u8);
+};
+
+void amd_register_ecc_decoder(void (*f)(int, struct mce *));
+void amd_unregister_ecc_decoder(void (*f)(int, struct mce *));
+
+#endif /* _EDAC_MCE_AMD_H */