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Thu, 9 Jan 2025 10:59:58 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id bdcVBS6sf2cBHQAAD6G6ig (envelope-from ); Thu, 09 Jan 2025 10:59:58 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: ddf6c193-ce78-11ef-99a4-01e77a169b0f DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1736420398; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=g9fM0R3rr4pnSw+2kXqv7pyWo8NS0rOHw9Y3B9boDRs=; b=BepEfmE9h6JLK+4zoc0ZwVB6hyIpIFbFhkdJukXnYYvtKxE/7KKu0H16wxlcbGik9meBk1 PNKlkJtc7h+aYgMPGWPfsZoixdLUS6WWjcZo93M0ygJ1vOlnryY3HuYT5IrhRIBY9aVd6F JVAmx/69DTHaCkCF/f7mVZAPpUzBKns= Authentication-Results: smtp-out2.suse.de; dkim=pass header.d=suse.com header.s=susede1 header.b=BepEfmE9 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1736420398; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=g9fM0R3rr4pnSw+2kXqv7pyWo8NS0rOHw9Y3B9boDRs=; b=BepEfmE9h6JLK+4zoc0ZwVB6hyIpIFbFhkdJukXnYYvtKxE/7KKu0H16wxlcbGik9meBk1 PNKlkJtc7h+aYgMPGWPfsZoixdLUS6WWjcZo93M0ygJ1vOlnryY3HuYT5IrhRIBY9aVd6F JVAmx/69DTHaCkCF/f7mVZAPpUzBKns= From: Juergen Gross To: xen-devel@lists.xenproject.org Cc: Juergen Gross , Andrew Cooper , Anthony PERARD , Michal Orzel , Jan Beulich , Julien Grall , =?utf-8?q?Roger_Pau_Monn=C3=A9?= , Stefano Stabellini Subject: [PATCH v7 3/7] xen/events: allow setting of global virq handler only for unbound virqs Date: Thu, 9 Jan 2025 11:59:31 +0100 Message-ID: <20250109105935.23585-4-jgross@suse.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250109105935.23585-1-jgross@suse.com> References: <20250109105935.23585-1-jgross@suse.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: 62BB21F393 X-Spamd-Result: default: False [-3.01 / 50.00]; BAYES_HAM(-3.00)[99.99%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_MISSING_CHARSET(0.50)[]; R_DKIM_ALLOW(-0.20)[suse.com:s=susede1]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:email,suse.com:dkim,suse.com:mid,imap1.dmz-prg2.suse.org:helo,imap1.dmz-prg2.suse.org:rdns]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; ASN(0.00)[asn:25478, ipnet:::/0, country:RU]; MIME_TRACE(0.00)[0:+]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; RCPT_COUNT_SEVEN(0.00)[9]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; FUZZY_BLOCKED(0.00)[rspamd.com]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; TO_DN_SOME(0.00)[]; DKIM_TRACE(0.00)[suse.com:+] X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Rspamd-Action: no action XEN_DOMCTL_set_virq_handler will happily steal a global virq from the current domain having bound it and assign it to another domain. The former domain will just never receive any further events for that virq without knowing what happened. Change the behavior to allow XEN_DOMCTL_set_virq_handler only if the virq in question is not bound by the current domain allowed to use it. Currently the only user of XEN_DOMCTL_set_virq_handler in the Xen code base is init-xenstore-domain, so changing the behavior like above will not cause any problems. Signed-off-by: Juergen Gross --- V6: - new patch --- xen/common/event_channel.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c index cd6f5a1211..4dba59efa2 100644 --- a/xen/common/event_channel.c +++ b/xen/common/event_channel.c @@ -991,7 +991,8 @@ void send_global_virq(uint32_t virq) int set_global_virq_handler(struct domain *d, uint32_t virq) { - struct domain *old; + struct domain *old, *hdl; + const struct vcpu *v; int rc = 0; if (virq >= NR_VIRQS) @@ -1023,7 +1024,22 @@ int set_global_virq_handler(struct domain *d, uint32_t virq) else { old = global_virq_handlers[virq]; - global_virq_handlers[virq] = d; + hdl = get_global_virq_handler(virq); + if ( hdl != d ) + { + read_lock(&hdl->event_lock); + + v = hdl->vcpu[0]; + if ( v && read_atomic(&v->virq_to_evtchn[virq]) ) + { + rc = -EBUSY; + old = d; + } + else + global_virq_handlers[virq] = d; + + read_unlock(&hdl->event_lock); + } } spin_unlock(&global_virq_handlers_lock);