From nobody Tue Feb 10 00:46:31 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=quarantine dis=none) header.from=proton.me ARC-Seal: i=1; a=rsa-sha256; t=1752111387; cv=none; d=zohomail.com; s=zohoarc; b=TiCz3c4e7LfeHF1+BjH+uSayRUrTh702hTKyo+EgibZ5+YjkmUs58fuAO34GwQqW/nCA2pQU7KkhxXNu++s5E5XoFuxfzJZ0SsCoP2PRyhEpBgEvGaAz6mYvntEla+6ShXKuD/jqI7wVdUIruNOsqZ/xRizC8kVvZfeNGpJaPrQ= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1752111387; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=LT/7KhgjabrfHiq7uxmJZ5O1+DPxq5bjarWhat+kddA=; b=mjBNCCddo8FWpghdjvuQZCxqY+U0qB8xSxkoP7qeHj+/ztSHgE6ZmtcUwywKRkkGeApy9eL9EcbujSL/FVRqxv+QQKojsv2CfHWY+rx32Bek21uV2TW347pQ+23EluN6rbzGOA5poMDnJSe9GZpeIONdlavYQ79hPBR2Lmr46s8= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=quarantine dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1752111387082173.95308924737628; Wed, 9 Jul 2025 18:36:27 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.1038864.1411035 (Exim 4.92) (envelope-from ) id 1uZgCf-0003TK-3W; Thu, 10 Jul 2025 01:36:01 +0000 Received: by outflank-mailman (output) from mailman id 1038864.1411035; Thu, 10 Jul 2025 01:36:01 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uZgCe-0003TC-W7; Thu, 10 Jul 2025 01:36:00 +0000 Received: by outflank-mailman (input) for mailman id 1038864; Thu, 10 Jul 2025 01:36:00 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uZgCc-0003T5-Rn for xen-devel@lists.xenproject.org; Thu, 10 Jul 2025 01:36:00 +0000 Received: from mail-10628.protonmail.ch (mail-10628.protonmail.ch [79.135.106.28]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 369bbad3-5d2e-11f0-a317-13f23c93f187; Thu, 10 Jul 2025 03:35:52 +0200 (CEST) X-Outflank-Mailman: Message body and most headers restored to incoming version 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: 369bbad3-5d2e-11f0-a317-13f23c93f187 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=proton.me; s=protonmail; t=1752111350; x=1752370550; bh=LT/7KhgjabrfHiq7uxmJZ5O1+DPxq5bjarWhat+kddA=; h=Date:To:From:Cc:Subject:Message-ID:Feedback-ID:From:To:Cc:Date: Subject:Reply-To:Feedback-ID:Message-ID:BIMI-Selector; b=S+MUqkcXAR+Jo3rkMFgj5fvNNvwiDhmzg/lnFeswh5A9gpNZNDEbaIr6LCs+9XGrm wc5/YGITHgJMAYU5D4oxISN44TA7BxdSf6QdTIz5e8tKI3OfK6NyucRd8OoRvig+I4 ql7w1qkQ2roh6JtokT2Rjr3gUXLkFI7McBhzBxwYIi/t1tGpkX3iPYbTg289v6/DXN Vu1VBbAZtENLvRK19ISyu8mey0BkocURvJOslbDRPnsNYZegnKoD6/JZY3DslA7BbW l8Bhahm69abGTEbjwDTN32vJx8KXC8Cm4TXVst9kmr1l6k/pOPM27QYZmDYLcmjY68 bjze9ASV3ac4g== Date: Thu, 10 Jul 2025 01:35:46 +0000 To: xen-devel@lists.xenproject.org From: dmkhn@proton.me Cc: andrew.cooper3@citrix.com, anthony.perard@vates.tech, jbeulich@suse.com, julien@xen.org, michal.orzel@amd.com, roger.pau@citrix.com, sstabellini@kernel.org, dmukhin@ford.com Subject: [PATCH v6] xen/console: introduce domain_console struct Message-ID: <20250710013421.2321353-1-dmukhin@ford.com> Feedback-ID: 123220910:user:proton X-Pm-Message-ID: fc6e71466682f5b2dd3197300ded3864775fba39 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @proton.me) X-ZM-MESSAGEID: 1752111388942116600 Content-Type: text/plain; charset="utf-8" From: Denis Mukhin =20 Introduce domain_console for grouping data structures used for integrating domain's diagnostic console with Xen's console driver. Group all pbuf-related data structures under domain_console. Rename the mov= ed fields to plain .buf, .idx and .lock names, since all uses of the fields are touched. Bump the domain console allocation size to the multiple of a cache line size (256). Rename domain console buffer size symbol to DOMAIN_CONSOLE_BUF_SIZE. Finally, update the domain_console allocation and initialization code. No functional change. Signed-off-by: Denis Mukhin --- Changes since v5: - updated commentary for the allocation size selection - updated the new data structure allocation size - added use of VLA for the domain console buffer Link to v5: https://lore.kernel.org/xen-devel/20250625002956.408945-1-dmukh= in@ford.com/ Link to CI: https://gitlab.com/xen-project/people/dmukhin/xen/-/pipelines/1= 917680099 --- xen/arch/arm/vpl011.c | 2 +- xen/arch/x86/hvm/hvm.c | 17 +++++++++-------- xen/arch/x86/pv/shim.c | 2 +- xen/common/domain.c | 21 +++++++++++---------- xen/drivers/char/console.c | 21 +++++++++++---------- xen/include/xen/sched.h | 33 +++++++++++++++++++++++---------- 6 files changed, 56 insertions(+), 40 deletions(-) diff --git a/xen/arch/arm/vpl011.c b/xen/arch/arm/vpl011.c index 2b6f2a09bca6..f4a840da10c5 100644 --- a/xen/arch/arm/vpl011.c +++ b/xen/arch/arm/vpl011.c @@ -713,7 +713,7 @@ int domain_vpl011_init(struct domain *d, struct vpl011_= init_info *info) } else { - d->console.input_allowed =3D true; + d->console->input_allowed =3D true; vpl011->backend_in_domain =3D false; =20 vpl011->backend.xen =3D xzalloc(struct vpl011_xen_backend); diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 56c7de39778b..2be98f6ccbd1 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -559,7 +559,8 @@ void hvm_do_resume(struct vcpu *v) static int cf_check hvm_print_line( int dir, unsigned int port, unsigned int bytes, uint32_t *val) { - struct domain *cd =3D current->domain; + const struct domain *d =3D current->domain; + struct domain_console *cons =3D d->console; char c =3D *val; =20 ASSERT(bytes =3D=3D 1 && port =3D=3D XEN_HVM_DEBUGCONS_IOPORT); @@ -571,16 +572,16 @@ static int cf_check hvm_print_line( if ( !is_console_printable(c) ) return X86EMUL_OKAY; =20 - spin_lock(&cd->pbuf_lock); + spin_lock(&cons->lock); if ( c !=3D '\n' ) - cd->pbuf[cd->pbuf_idx++] =3D c; - if ( (cd->pbuf_idx =3D=3D (DOMAIN_PBUF_SIZE - 1)) || (c =3D=3D '\n') ) + cons->buf[cons->idx++] =3D c; + if ( (cons->idx =3D=3D (DOMAIN_CONSOLE_BUF_SIZE - 1)) || (c =3D=3D '\n= ') ) { - cd->pbuf[cd->pbuf_idx] =3D '\0'; - guest_printk(cd, XENLOG_G_DEBUG "%s\n", cd->pbuf); - cd->pbuf_idx =3D 0; + cons->buf[cons->idx] =3D '\0'; + guest_printk(d, XENLOG_G_DEBUG "%s\n", cons->buf); + cons->idx =3D 0; } - spin_unlock(&cd->pbuf_lock); + spin_unlock(&cons->lock); =20 return X86EMUL_OKAY; } diff --git a/xen/arch/x86/pv/shim.c b/xen/arch/x86/pv/shim.c index bc2a7dd5fae5..bd29c53a2d34 100644 --- a/xen/arch/x86/pv/shim.c +++ b/xen/arch/x86/pv/shim.c @@ -239,7 +239,7 @@ void __init pv_shim_setup_dom(struct domain *d, l4_pgen= try_t *l4start, */ d->max_pages =3D domain_tot_pages(d); =20 - d->console.input_allowed =3D true; + d->console->input_allowed =3D true; } =20 static void write_start_info(struct domain *d) diff --git a/xen/common/domain.c b/xen/common/domain.c index 303c338ef293..3ffefcbbff77 100644 --- a/xen/common/domain.c +++ b/xen/common/domain.c @@ -669,7 +669,7 @@ static void _domain_destroy(struct domain *d) BUG_ON(!d->is_dying); BUG_ON(atomic_read(&d->refcnt) !=3D DOMAIN_DESTROYED); =20 - xfree(d->pbuf); + xfree(d->console); =20 argo_destroy(d); =20 @@ -835,8 +835,6 @@ struct domain *domain_create(domid_t domid, flags |=3D CDF_hardware; if ( old_hwdom ) old_hwdom->cdf &=3D ~CDF_hardware; - - d->console.input_allowed =3D true; } =20 /* Holding CDF_* internal flags. */ @@ -866,8 +864,6 @@ struct domain *domain_create(domid_t domid, spin_lock_init(&d->shutdown_lock); d->shutdown_code =3D SHUTDOWN_CODE_INVALID; =20 - spin_lock_init(&d->pbuf_lock); - rwlock_init(&d->vnuma_rwlock); =20 #ifdef CONFIG_HAS_PCI @@ -877,6 +873,16 @@ struct domain *domain_create(domid_t domid, =20 /* All error paths can depend on the above setup. */ =20 + BUILD_BUG_ON(DOMAIN_CONSOLE_BUF_SIZE <=3D 0); + + err =3D -ENOMEM; + d->console =3D xzalloc_bytes(DOMAIN_CONSOLE_SIZE); + if ( !d->console ) + goto fail; + + spin_lock_init(&d->console->lock); + d->console->input_allowed =3D is_hardware_domain(d); + /* * Allocate d->vcpu[] and set ->max_vcpus up early. Various per-domain * resources want to be sized based on max_vcpus. @@ -959,11 +965,6 @@ struct domain *domain_create(domid_t domid, if ( (err =3D argo_init(d)) !=3D 0 ) goto fail; =20 - err =3D -ENOMEM; - d->pbuf =3D xzalloc_array(char, DOMAIN_PBUF_SIZE); - if ( !d->pbuf ) - goto fail; - if ( (err =3D sched_init_domain(d, config->cpupool_id)) !=3D 0 ) goto fail; =20 diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c index f54632bc0811..469f5e8832da 100644 --- a/xen/drivers/char/console.c +++ b/xen/drivers/char/console.c @@ -526,7 +526,7 @@ struct domain *console_get_domain(void) if ( !d ) return NULL; =20 - if ( d->console.input_allowed ) + if ( d->console->input_allowed ) return d; =20 rcu_unlock_domain(d); @@ -569,7 +569,7 @@ static void console_switch_input(void) { rcu_unlock_domain(d); =20 - if ( !d->console.input_allowed ) + if ( !d->console->input_allowed ) continue; =20 console_rx =3D next_rx; @@ -788,6 +788,7 @@ static long guest_console_write(XEN_GUEST_HANDLE_PARAM(= char) buffer, else { char *kin =3D kbuf, *kout =3D kbuf, c; + struct domain_console *cons =3D cd->console; =20 /* Strip non-printable characters */ do @@ -800,22 +801,22 @@ static long guest_console_write(XEN_GUEST_HANDLE_PARA= M(char) buffer, } while ( --kcount > 0 ); =20 *kout =3D '\0'; - spin_lock(&cd->pbuf_lock); + spin_lock(&cons->lock); kcount =3D kin - kbuf; if ( c !=3D '\n' && - (cd->pbuf_idx + (kout - kbuf) < (DOMAIN_PBUF_SIZE - 1)) ) + (cons->idx + (kout - kbuf) < (DOMAIN_CONSOLE_BUF_SIZE - 1= )) ) { /* buffer the output until a newline */ - memcpy(cd->pbuf + cd->pbuf_idx, kbuf, kout - kbuf); - cd->pbuf_idx +=3D (kout - kbuf); + memcpy(cons->buf + cons->idx, kbuf, kout - kbuf); + cons->idx +=3D kout - kbuf; } else { - cd->pbuf[cd->pbuf_idx] =3D '\0'; - guest_printk(cd, XENLOG_G_DEBUG "%s%s\n", cd->pbuf, kbuf); - cd->pbuf_idx =3D 0; + cons->buf[cons->idx] =3D '\0'; + guest_printk(cd, XENLOG_G_DEBUG "%s%s\n", cons->buf, kbuf); + cons->idx =3D 0; } - spin_unlock(&cd->pbuf_lock); + spin_unlock(&cons->lock); } =20 guest_handle_add_offset(buffer, kcount); diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h index fe53d4fab7ba..006937d32260 100644 --- a/xen/include/xen/sched.h +++ b/xen/include/xen/sched.h @@ -35,6 +35,8 @@ DEFINE_XEN_GUEST_HANDLE(vcpu_runstate_info_compat_t); #endif =20 +struct domain_console; + /* * Stats * @@ -371,6 +373,26 @@ struct evtchn_port_ops; =20 #define MAX_NR_IOREQ_SERVERS 8 =20 +/* + * Domain console settings is the dynamically-allocated data structure. + * Using an even multiple of a cache line size may help to optimize the + * allocation overhead. + */ +#define DOMAIN_CONSOLE_SIZE ROUNDUP(256, SMP_CACHE_BYTES) +#define DOMAIN_CONSOLE_BUF_SIZE (DOMAIN_CONSOLE_SIZE - \ + sizeof(struct domain_console)) + +/* Domain console settings. */ +struct domain_console { + /* Permission to take ownership of the physical console input. */ + bool input_allowed; + + /* hvm_print_line() and guest_console_write() logging. */ + unsigned int idx; + spinlock_t lock; + char buf[0]; +}; + struct domain { domid_t domain_id; @@ -562,12 +584,6 @@ struct domain /* Control-plane tools handle for this domain. */ xen_domain_handle_t handle; =20 - /* hvm_print_line() and guest_console_write() logging. */ -#define DOMAIN_PBUF_SIZE 200 - char *pbuf; - unsigned int pbuf_idx; - spinlock_t pbuf_lock; - /* OProfile support. */ struct xenoprof *xenoprof; =20 @@ -653,10 +669,7 @@ struct domain #endif =20 /* Console settings. */ - struct { - /* Permission to take ownership of the physical console input. */ - bool input_allowed; - } console; + struct domain_console *console; } __aligned(PAGE_SIZE); =20 static inline struct page_list_head *page_to_list( --=20 2.34.1