RE: [Question] review links are disappearing from the qemu-devel mailing-list

[Salil Mehta <salil.mehta@huawei.com>]

[-- Attachment #1: Type: text/plain, Size: 1496 bytes --]

Hi Eric,

> From: Eric Wong <e@80x24.org>
> Sent: Tuesday, November 14, 2023 3:33 PM
> To: Salil Mehta <salil.mehta@huawei.com>
> 
> Salil Mehta <salil.mehta@huawei.com> wrote:
> > I have cross confirmed the behavior with other people across companies and
> > all of them are having issues in viewing above links. Surprising part is
> > these were present at the first instance when the review comments were floated
> > by Igor - I can assure you that.
> 
> Does my lore mirror work for you?
> 
> https://yhbt.net/lore/qemu-
> devel/20231027145652.44cc845c@imammedo.users.ipa.redhat.com/
> 
> It's running off residential Internet via reverse SSH tunnel
> to a cheap VPS, so uptime is sporadic, but usually it's up...

Yes, but only for first link 

https://yhbt.net/lore/qemu-devel/20231027145652.44cc845c@imammedo.users.ipa.redhat.com/

Attachment:
1. yhbt.net_lore_qemu-devel_20231027145652.44cc845c@imammedo.users.ipa.redhat.com_raw.eml
2. Re_ [PATCH V6 1_9] accel_kvm_ Extract common KVM vCPU {creation,parking} code - Igor Mammedov


Rest other below link end up in 'Not found'

https://yhbt.net/lore/qemu-devel/20231027150536.3c481246@imammedo.users.ipa.redhat.com/
https://yhbt.net/lore/qemu-devel/20231027160814.3f47ff70@imammedo.users.ipa.redhat.com/
https://yhbt.net/lore/qemu-devel/20231027154648.2ce47292@imammedo.users.ipa.redhat.com/
https://yhbt.net/lore/qemu-devel/20231027151828.5c9d499b@imammedo.users.ipa.redhat.com/


Thanks
Salil.



[-- Attachment #2: _20231027150536.3c481246@imammedo.users.ipa.redhat.com_ not found.pdf --]
[-- Type: application/pdf, Size: 64169 bytes --]

[-- Attachment #3: _20231027151828.5c9d499b@imammedo.users.ipa.redhat.com_ not found.pdf --]
[-- Type: application/pdf, Size: 64577 bytes --]

[-- Attachment #4: _20231027154648.2ce47292@imammedo.users.ipa.redhat.com_ not found.pdf --]
[-- Type: application/pdf, Size: 65101 bytes --]

[-- Attachment #5: _20231027160814.3f47ff70@imammedo.users.ipa.redhat.com_ not found.pdf --]
[-- Type: application/pdf, Size: 64470 bytes --]

[-- Attachment #6: Re_ [PATCH V6 1_9] accel_kvm_ Extract common KVM vCPU {creation,parking} code - Igor Mammedov.pdf --]
[-- Type: application/pdf, Size: 166534 bytes --]

[-- Attachment #7: yhbt.net_lore_qemu-devel_20231027145652.44cc845c@imammedo.users.ipa.redhat.com_raw.eml --]
[-- Type: application/octet-stream, Size: 14474 bytes --]

From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
	aws-us-west-2-korg-lkml-1.web.codeaurora.org
Received: from lists.gnu.org (lists.gnu.org [209.51.188.17])
	(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
	(No client certificate requested)
	by smtp.lore.kernel.org (Postfix) with ESMTPS id E80D4C4332F
	for <qemu-devel@archiver.kernel.org>; Tue,  7 Nov 2023 13:51:17 +0000 (UTC)
Received: from localhost ([::1] helo=lists1p.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.90_1)
	(envelope-from <qemu-devel-bounces@nongnu.org>)
	id 1r0MTe-0003zb-6E; Tue, 07 Nov 2023 08:50:46 -0500
Received: from eggs.gnu.org ([2001:470:142:3::10])
 by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
 (Exim 4.90_1) (envelope-from <mst@redhat.com>) id 1r0MTc-0003kI-2J
 for qemu-devel@nongnu.org; Tue, 07 Nov 2023 08:50:44 -0500
Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124])
 by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
 (Exim 4.90_1) (envelope-from <mst@redhat.com>) id 1r0MTZ-00089b-T8
 for qemu-devel@nongnu.org; Tue, 07 Nov 2023 08:50:43 -0500
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;
 s=mimecast20190719; t=1699365040;
 h=from:from:reply-to:subject:subject:date:date:message-id:message-id:
 to:to:cc:cc:mime-version:mime-version:content-type:content-type:
 content-transfer-encoding:content-transfer-encoding:resent-to:
 resent-from:resent-message-id:in-reply-to:in-reply-to:  references:references; 
 bh=oJitzRlD+4efw2WkN5qAXdFYOyGL7volVXYBUrGuI/s=;
 b=itUPDiJberHSsfJqWkQV2m8VfihctQy9cpjSFiQ7pvU4/VE3t9KvFYIrvd4lHDWV9pbyWs
 /Q+nqaOCrM13RXrVMcVnxyvRVMxnDGLNem7eYUL7fnrgfhNXnX+uaquQOlRDpa+hX8viJD
 i1hVDHO7vO9l2iAwryV21CmcOgrOkVU=
Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com
 [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS
 (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id
 us-mta-184-w0uZv8AgPie0DkZLtKh6bA-1; Tue, 07 Nov 2023 08:50:34 -0500
X-MC-Unique: w0uZv8AgPie0DkZLtKh6bA-1
Received: by mail-wm1-f71.google.com with SMTP id
 5b1f17b1804b1-40855a91314so37564485e9.1
 for <qemu-devel@nongnu.org>; Tue, 07 Nov 2023 05:50:34 -0800 (PST)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20230601; t=1699365033; x=1699969833;
 h=content-transfer-encoding:mime-version:references:in-reply-to
 :message-id:subject:cc:to:from:date:resent-to:resent-message-id
 :resent-date:resent-from:x-gm-message-state:from:to:cc:subject:date
 :message-id:reply-to;
 bh=oJitzRlD+4efw2WkN5qAXdFYOyGL7volVXYBUrGuI/s=;
 b=Y+arq3oLfgkytf6od377DmFm7n8J0OSe1vo3iw1i5QtR5C0tXFfbiVoDs3HFkd/OGC
 Tn1cmq2qgg3FknFVAgvURQ4Qq35jT7wtwUKRnvy95Ct1q1wj1Aw8mjrdf8hqtmSznH7I
 Rhoj0B/05tYcjyz/eWqtK2UsMu3TuC7O+dn5Sp3pGcGtY+CO8CqZ5fK7elFYsjpCO8f4
 ZQYiJ+tqbfdGaOb8wUDPptsjiPZhavBjRns3xFUmOFQI82NXF1bUTQSOs+pXiEYqji4Y
 25Yj8u/GwPrRQ7eEbQyB1sQJ6XucjlkWzjyDB3kOGMuv2EIvNehbg/Wi+I61PICFPsZu
 kkJQ==
X-Gm-Message-State: AOJu0YyIz1Q8hDSc9oZaIS+SKAe90t78XDDtRMOPMQEnUathP+fyeXiB
 UT44NThjZvzUwf/U929A8LK3D9kwMr/PvpM+/NXVH98mJZtLKxqinx5fWTdedGK8EqG4pONb74y
 dRTQmEtVG5dS+6KWmEw9Xrm6afvdRKxiVyZmhP2svuZZ0xztOKJpLOU6cVnEjEgfFsOiC/GrMqB
 EMyeTupslTjY+zhxzqhVQD9dKn6Z3frAStbTna0avlSkE9
X-Received: by 2002:a05:600c:3c8f:b0:402:e68f:8a4f with SMTP id
 bg15-20020a05600c3c8f00b00402e68f8a4fmr3141923wmb.0.1699365032653; 
 Tue, 07 Nov 2023 05:50:32 -0800 (PST)
X-Google-Smtp-Source: AGHT+IHWFbXJzpHCNGC4qv/znwcvL6Y/DwYV+xXMxJbci+OQS7MFinlcN92P/Y3OHzOoPkdf/z+A/A==
X-Received: by 2002:a05:600c:3c8f:b0:402:e68f:8a4f with SMTP id
 bg15-20020a05600c3c8f00b00402e68f8a4fmr3141893wmb.0.1699365031951; 
 Tue, 07 Nov 2023 05:50:31 -0800 (PST)
Received: from redhat.com ([2a02:14f:1f1:373a:140:63a8:a31c:ab2a])
 by smtp.gmail.com with ESMTPSA id
 c14-20020a05600c0a4e00b004030e8ff964sm16434245wmq.34.2023.11.07.05.50.30
 for <qemu-devel@nongnu.org>
 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);
 Tue, 07 Nov 2023 05:50:31 -0800 (PST)
Resent-From: "Michael S. Tsirkin" <mst@redhat.com>
Resent-Date: Tue, 7 Nov 2023 08:50:28 -0500
Resent-Message-ID: <ZUpApD3B0AByD90W@redhat.com>
Resent-To: qemu-devel@nongnu.org
Received: from imammedo.users.ipa.redhat.com (nat-pool-brq-t.redhat.com.
 [213.175.37.10]) by smtp.gmail.com with ESMTPSA id
 k13-20020a17090666cd00b009b65a834dd6sm1168699ejp.215.2023.10.27.05.56.53
 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);
 Fri, 27 Oct 2023 05:56:55 -0700 (PDT)
Date: Fri, 27 Oct 2023 14:56:52 +0200
From: Igor Mammedov <imammedo@redhat.com>
To: Salil Mehta <salil.mehta@huawei.com>
Cc: <qemu-devel@nongnu.org>, <qemu-arm@nongnu.org>, <maz@kernel.org>,
 <jean-philippe@linaro.org>, <jonathan.cameron@huawei.com>,
 <lpieralisi@kernel.org>, <peter.maydell@linaro.org>,
 <richard.henderson@linaro.org>, <andrew.jones@linux.dev>,
 <david@redhat.com>, <philmd@linaro.org>, <eric.auger@redhat.com>,
 <oliver.upton@linux.dev>, <pbonzini@redhat.com>, <mst@redhat.com>,
 <will@kernel.org>, <gshan@redhat.com>, <rafael@kernel.org>,
 <alex.bennee@linaro.org>, <linux@armlinux.org.uk>,
 <darren@os.amperecomputing.com>, <ilkka@os.amperecomputing.com>,
 <vishnu@os.amperecomputing.com>, <karl.heubaum@oracle.com>,
 <miguel.luis@oracle.com>, <salil.mehta@opnsrc.net>,
 <zhukeqian1@huawei.com>, <wangxiongfeng2@huawei.com>,
 <wangyanan55@huawei.com>, <jiakernel2@gmail.com>, <maobibo@loongson.cn>,
 <lixianglai@loongson.cn>, <linuxarm@huawei.com>
Subject: Re: [PATCH V6 1/9] accel/kvm: Extract common KVM vCPU
 {creation,parking} code
Message-ID: <20231027145652.44cc845c@imammedo.users.ipa.redhat.com>
In-Reply-To: <20231013105129.25648-2-salil.mehta@huawei.com>
References: <20231013105129.25648-1-salil.mehta@huawei.com>
 <20231013105129.25648-2-salil.mehta@huawei.com>
X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; x86_64-redhat-linux-gnu)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Received-SPF: pass client-ip=170.10.133.124; envelope-from=mst@redhat.com;
 helo=us-smtp-delivery-124.mimecast.com
X-Spam_score_int: -20
X-Spam_score: -2.1
X-Spam_bar: --
X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001,
 DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,
 RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001,
 SPF_HELO_NONE=0.001, SPF_PASS=-0.001,
 T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable autolearn_force=no
X-Spam_action: no action
X-BeenThere: qemu-devel@nongnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
 <mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <https://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
 <mailto:qemu-devel-request@nongnu.org?subject=subscribe>
Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org
Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org

On Fri, 13 Oct 2023 11:51:21 +0100
Salil Mehta <salil.mehta@huawei.com> wrote:

> KVM vCPU creation is done once during the initialization of the VM when Qemu
                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> thread is spawned. This is common to all the architectures.

is it really true fox x86?

> 
> Hot-unplug of vCPU results in destruction of the vCPU object in QOM but the
> corresponding KVM vCPU object in the Host KVM is not destroyed and its
                                                                ^
since KVM doesn't support vCPU removal

> representative KVM vCPU object/context in Qemu is parked.
> 
> Refactor common logic so that some APIs could be reused by vCPU Hotplug code.
'reused' part doesn't happen within this series. So a reason
why patch exists is not clear/no one can deduce the reason
without the actual user here.

Suggest to move it to a series that actually will use this patch.


> Update new/old APIs with trace events instead of DTRACE.
> 
> Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
> Reviewed-by: Gavin Shan <gshan@redhat.com>
> Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Tested-by: Xianglai Li <lixianglai@loongson.cn>
> ---
>  accel/kvm/kvm-all.c    | 64 ++++++++++++++++++++++++++++++++----------
>  accel/kvm/trace-events |  4 +++
>  include/sysemu/kvm.h   | 16 +++++++++++
>  3 files changed, 69 insertions(+), 15 deletions(-)
> 
> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
> index 72e1d1141c..bfa7816aaa 100644
> --- a/accel/kvm/kvm-all.c
> +++ b/accel/kvm/kvm-all.c
> @@ -137,6 +137,7 @@ static QemuMutex kml_slots_lock;
>  #define kvm_slots_unlock()  qemu_mutex_unlock(&kml_slots_lock)
>  
>  static void kvm_slot_init_dirty_bitmap(KVMSlot *mem);
> +static int kvm_get_vcpu(KVMState *s, unsigned long vcpu_id);
>  
>  static inline void kvm_resample_fd_remove(int gsi)
>  {
> @@ -320,14 +321,53 @@ err:
>      return ret;
>  }
>  
> +void kvm_park_vcpu(CPUState *cpu)
> +{
> +    struct KVMParkedVcpu *vcpu;
> +
> +    trace_kvm_park_vcpu(cpu->cpu_index, kvm_arch_vcpu_id(cpu));
> +
> +    vcpu = g_malloc0(sizeof(*vcpu));
> +    vcpu->vcpu_id = kvm_arch_vcpu_id(cpu);
> +    vcpu->kvm_fd = cpu->kvm_fd;
> +    QLIST_INSERT_HEAD(&kvm_state->kvm_parked_vcpus, vcpu, node);
> +}
> +
> +int kvm_create_vcpu(CPUState *cpu)
> +{
> +    unsigned long vcpu_id = kvm_arch_vcpu_id(cpu);
> +    KVMState *s = kvm_state;
> +    int kvm_fd;
> +
> +    trace_kvm_create_vcpu(cpu->cpu_index, kvm_arch_vcpu_id(cpu));
> +
> +    /* check if the KVM vCPU already exist but is parked */
> +    kvm_fd = kvm_get_vcpu(s, vcpu_id);
> +    if (kvm_fd < 0) {
> +        /* vCPU not parked: create a new KVM vCPU */
> +        kvm_fd = kvm_vm_ioctl(s, KVM_CREATE_VCPU, vcpu_id);
> +        if (kvm_fd < 0) {
> +            error_report("KVM_CREATE_VCPU IOCTL failed for vCPU %lu", vcpu_id);
> +            return kvm_fd;
> +        }
> +    }
> +
> +    cpu->kvm_fd = kvm_fd;
> +    cpu->kvm_state = s;
> +    cpu->vcpu_dirty = true;
> +    cpu->dirty_pages = 0;
> +    cpu->throttle_us_per_full = 0;
> +
> +    return 0;
> +}
> +
>  static int do_kvm_destroy_vcpu(CPUState *cpu)
>  {
>      KVMState *s = kvm_state;
>      long mmap_size;
> -    struct KVMParkedVcpu *vcpu = NULL;
>      int ret = 0;
>  
> -    DPRINTF("kvm_destroy_vcpu\n");
> +    trace_kvm_destroy_vcpu(cpu->cpu_index, kvm_arch_vcpu_id(cpu));
>  
>      ret = kvm_arch_destroy_vcpu(cpu);
>      if (ret < 0) {
> @@ -353,10 +393,7 @@ static int do_kvm_destroy_vcpu(CPUState *cpu)
>          }
>      }
>  
> -    vcpu = g_malloc0(sizeof(*vcpu));
> -    vcpu->vcpu_id = kvm_arch_vcpu_id(cpu);
> -    vcpu->kvm_fd = cpu->kvm_fd;
> -    QLIST_INSERT_HEAD(&kvm_state->kvm_parked_vcpus, vcpu, node);
> +    kvm_park_vcpu(cpu);
>  err:
>      return ret;
>  }
> @@ -377,6 +414,8 @@ static int kvm_get_vcpu(KVMState *s, unsigned long vcpu_id)
>          if (cpu->vcpu_id == vcpu_id) {
>              int kvm_fd;
>  
> +            trace_kvm_get_vcpu(vcpu_id);
> +
>              QLIST_REMOVE(cpu, node);
>              kvm_fd = cpu->kvm_fd;
>              g_free(cpu);
> @@ -384,7 +423,7 @@ static int kvm_get_vcpu(KVMState *s, unsigned long vcpu_id)
>          }
>      }
>  
> -    return kvm_vm_ioctl(s, KVM_CREATE_VCPU, (void *)vcpu_id);
> +    return -ENOENT;
>  }
>  
>  int kvm_init_vcpu(CPUState *cpu, Error **errp)
> @@ -395,19 +434,14 @@ int kvm_init_vcpu(CPUState *cpu, Error **errp)
>  
>      trace_kvm_init_vcpu(cpu->cpu_index, kvm_arch_vcpu_id(cpu));
>  
> -    ret = kvm_get_vcpu(s, kvm_arch_vcpu_id(cpu));
> +    ret = kvm_create_vcpu(cpu);
>      if (ret < 0) {
> -        error_setg_errno(errp, -ret, "kvm_init_vcpu: kvm_get_vcpu failed (%lu)",
> +        error_setg_errno(errp, -ret,
> +                         "kvm_init_vcpu: kvm_create_vcpu failed (%lu)",
>                           kvm_arch_vcpu_id(cpu));
>          goto err;
>      }
>  
> -    cpu->kvm_fd = ret;
> -    cpu->kvm_state = s;
> -    cpu->vcpu_dirty = true;
> -    cpu->dirty_pages = 0;
> -    cpu->throttle_us_per_full = 0;
> -
>      mmap_size = kvm_ioctl(s, KVM_GET_VCPU_MMAP_SIZE, 0);
>      if (mmap_size < 0) {
>          ret = mmap_size;
> diff --git a/accel/kvm/trace-events b/accel/kvm/trace-events
> index 399aaeb0ec..cdd0c95c09 100644
> --- a/accel/kvm/trace-events
> +++ b/accel/kvm/trace-events
> @@ -9,6 +9,10 @@ kvm_device_ioctl(int fd, int type, void *arg) "dev fd %d, type 0x%x, arg %p"
>  kvm_failed_reg_get(uint64_t id, const char *msg) "Warning: Unable to retrieve ONEREG %" PRIu64 " from KVM: %s"
>  kvm_failed_reg_set(uint64_t id, const char *msg) "Warning: Unable to set ONEREG %" PRIu64 " to KVM: %s"
>  kvm_init_vcpu(int cpu_index, unsigned long arch_cpu_id) "index: %d id: %lu"
> +kvm_create_vcpu(int cpu_index, unsigned long arch_cpu_id) "index: %d id: %lu"
> +kvm_get_vcpu(unsigned long arch_cpu_id) "id: %lu"
> +kvm_destroy_vcpu(int cpu_index, unsigned long arch_cpu_id) "index: %d id: %lu"
> +kvm_park_vcpu(int cpu_index, unsigned long arch_cpu_id) "index: %d id: %lu"
>  kvm_irqchip_commit_routes(void) ""
>  kvm_irqchip_add_msi_route(char *name, int vector, int virq) "dev %s vector %d virq %d"
>  kvm_irqchip_update_msi_route(int virq) "Updating MSI route virq=%d"
> diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
> index ee9025f8e9..8137e6a44c 100644
> --- a/include/sysemu/kvm.h
> +++ b/include/sysemu/kvm.h
> @@ -465,6 +465,22 @@ void kvm_set_sigmask_len(KVMState *s, unsigned int sigmask_len);
>  int kvm_physical_memory_addr_from_host(KVMState *s, void *ram_addr,
>                                         hwaddr *phys_addr);
>  
> +/**
> + * kvm_create_vcpu - Gets a parked KVM vCPU or creates a KVM vCPU
> + * @cpu: QOM CPUState object for which KVM vCPU has to be fetched/created.
> + *
> + * @returns: 0 when success, errno (<0) when failed.
> + */
> +int kvm_create_vcpu(CPUState *cpu);
> +
> +/**
> + * kvm_park_vcpu - Park QEMU KVM vCPU context
> + * @cpu: QOM CPUState object for which QEMU KVM vCPU context has to be parked.
> + *
> + * @returns: none
> + */
> +void kvm_park_vcpu(CPUState *cpu);
> +
>  #endif /* NEED_CPU_H */
>  
>  void kvm_cpu_synchronize_state(CPUState *cpu);