Revision c15e0ae42c8e5a61e9aca8aac920517cf7b3e94e authored by Li RongQing on 09 March 2022, 08:35:44 UTC, committed by Paolo Bonzini on 02 April 2022, 09:37:27 UTC
If apic_id is less than min, and (max - apic_id) is greater than
KVM_IPI_CLUSTER_SIZE, then the third check condition is satisfied but
the new apic_id does not fit the bitmask.  In this case __send_ipi_mask
should send the IPI.

This is mostly theoretical, but it can happen if the apic_ids on three
iterations of the loop are for example 1, KVM_IPI_CLUSTER_SIZE, 0.

Fixes: aaffcfd1e82 ("KVM: X86: Implement PV IPIs in linux guest")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Message-Id: <1646814944-51801-1-git-send-email-lirongqing@baidu.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 parent 2a8859f
Raw File
shuffle.h
// SPDX-License-Identifier: GPL-2.0
// Copyright(c) 2018 Intel Corporation. All rights reserved.
#ifndef _MM_SHUFFLE_H
#define _MM_SHUFFLE_H
#include <linux/jump_label.h>

#define SHUFFLE_ORDER (MAX_ORDER-1)

#ifdef CONFIG_SHUFFLE_PAGE_ALLOCATOR
DECLARE_STATIC_KEY_FALSE(page_alloc_shuffle_key);
extern void __shuffle_free_memory(pg_data_t *pgdat);
extern bool shuffle_pick_tail(void);
static inline void __meminit shuffle_free_memory(pg_data_t *pgdat)
{
	if (!static_branch_unlikely(&page_alloc_shuffle_key))
		return;
	__shuffle_free_memory(pgdat);
}

extern void __shuffle_zone(struct zone *z);
static inline void __meminit shuffle_zone(struct zone *z)
{
	if (!static_branch_unlikely(&page_alloc_shuffle_key))
		return;
	__shuffle_zone(z);
}

static inline bool is_shuffle_order(int order)
{
	if (!static_branch_unlikely(&page_alloc_shuffle_key))
		return false;
	return order >= SHUFFLE_ORDER;
}
#else
static inline bool shuffle_pick_tail(void)
{
	return false;
}

static inline void shuffle_free_memory(pg_data_t *pgdat)
{
}

static inline void shuffle_zone(struct zone *z)
{
}

static inline bool is_shuffle_order(int order)
{
	return false;
}
#endif
#endif /* _MM_SHUFFLE_H */
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