From nobody Mon Feb 9 18:18:36 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=quarantine dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1769491268; cv=none; d=zohomail.com; s=zohoarc; b=iwAzdnyu2Qae2Qbl//XK3clCdwWWIN0xji70yCNwz7xvgLLG3T5+kjj4+CJTzC+8UfyzLvcKFjWozZVvtGgxbbj7BYiVRndLHld5JuA1TlRVXHB00/STSmxo+B1/CzPdMpAtdKeTqT2w3JMRqgQOra4v7LOfaO2PLL/mNO+3e7Y= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1769491268; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=ampkMXpvZM0Uh9Dio1wYKLx68wPyoO/FMFpvVez+X64=; b=igB2XSDjI8WwzpDbuqbA1mk3zuBYRvHDcrx9PmR+3Tj1oWS8TRkV6rw29hRp2gH/uuASSQJ0jQCTBUuL6JycyAV+7U8GlYodN7cyglgcdrqTPKuHcwL61BJuS8dX6hW02ZCjhKhL6/dG3lNgO/kuYKRs2lk528EgVDD0CLKzFsc= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=quarantine dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1769491268943398.40527908702734; Mon, 26 Jan 2026 21:21:08 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vkbTf-0001it-Cb; Tue, 27 Jan 2026 00:18:59 -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 ) id 1vkbSv-0000Ut-Jh for qemu-devel@nongnu.org; Tue, 27 Jan 2026 00:18:15 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vkbSu-0000Gx-5l for qemu-devel@nongnu.org; Tue, 27 Jan 2026 00:18:13 -0500 Received: from mail-pj1-f71.google.com (mail-pj1-f71.google.com [209.85.216.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-553-f4FUNuPHN9efHIyW_eSVNg-1; Tue, 27 Jan 2026 00:18:09 -0500 Received: by mail-pj1-f71.google.com with SMTP id 98e67ed59e1d1-34c93f0849dso4945604a91.1 for ; Mon, 26 Jan 2026 21:18:09 -0800 (PST) Received: from rhel9-box.lan ([122.163.48.79]) by smtp.googlemail.com with ESMTPSA id 98e67ed59e1d1-353f6230d5dsm1110925a91.17.2026.01.26.21.18.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jan 2026 21:18:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1769491091; h=from:from:reply-to:subject:subject: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=ampkMXpvZM0Uh9Dio1wYKLx68wPyoO/FMFpvVez+X64=; b=U13JmB55MUIH/uXmETuzFGm/00rQ90MHZ5wIxhpflumtoz1XFX3yTIy92fQckAH4vepe4u mg5x6tr/GZ+Jgc+ozN0gQh5GK39LXOKGz0z3E2tg2yjmuksHIPThm8F7CP8hOk+5ZXVWcl lPojOjOwZHk055VpX8x1NJ3I2YNQRAg= X-MC-Unique: f4FUNuPHN9efHIyW_eSVNg-1 X-Mimecast-MFC-AGG-ID: f4FUNuPHN9efHIyW_eSVNg_1769491088 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1769491088; x=1770095888; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=ampkMXpvZM0Uh9Dio1wYKLx68wPyoO/FMFpvVez+X64=; b=S3otqL6fDxErlRNspkVeqaPT0vx437txvFFo3gQoE29BBoxffbBP2xcr6XJYs9eadd LH3hhqitAhhLHMrxDmZ3hCnRrqoGM1/Vc0YxtOBBGmb74wRi0gaFjBGKUPye5iCrTxqJ 7KYP15zplvJd5Qci8ev4E384J9qBqLpmQRYtShC/FrLy+rbPL1pOnH9ip7txZlg57UYt Tk0c8QkqGhYnXz5Lf0EFwTfO0mrDxhFHcvlnm8OuA8oPJGb26Wp5NKspChKHV6i1LbOp 0Tq/ZJLoxPD2QeBY8qtwD90WPeEolIdDwTJKt59YSupJeJxcWqu98Zn35FXP1yRDUFLF V4aw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769491088; x=1770095888; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=ampkMXpvZM0Uh9Dio1wYKLx68wPyoO/FMFpvVez+X64=; b=NKMD3S8zL6WbVdW+1CT7kY6C8pfbM4oOS6opB8HZZ3GBgK/Nt8yuTxHYGNf57Ta1DR jDsuSmzenHPtBT5LFA1xlqriGxMDNPqmif8PzU8pVITrqMwWha0LxGUqYt8c5+IZa4yi Dkn0cOPqyHdguvX35l0eL1aopz0MDnUqGD3ghOy/ohhDq7finpmeRru62q+2aCMYuHfb QsbFibhnexBbO5w6kJ4ut4hefFUIvBfta4/rH32cCG/H3uFlS/zrNTelfY6tEhtKQ0Kz paaHE//YaiDAsv14KbMPhTkuQo+BRThxQKpo1Mn9kfk6rnZIMSS6v8HLwLaWJCXwefxi gXIg== X-Forwarded-Encrypted: i=1; AJvYcCUVsvw788UJj8mh1CuCEwdMtaURgIJZBF8Q1dRCTmVPTJSscShSyvAcpUGE1yzaLewzklQKGUg1044j@nongnu.org X-Gm-Message-State: AOJu0Yzo96HNB21ksBhRkouLrz3stDOBrv1Qlx4NsVmGKM2zHLZbIaE1 XY6v4bLKnOB1c0ZDll5mS2+GvxZVo+2rC8jIqWnhSq7aSW+sXJg2Nd/OjrANBSdvr/IdHshEwJh kkvyZeCsvuIzvIqPeW4frArkG/FzQpTPAMueg20E4ynz63aQFw6EvNtUu X-Gm-Gg: AZuq6aKSh1a5e0fTTCCtxsZ4M5O0uSvyVC2B4yGhP+LFny/uCrbQB4xSgDLsOXzB2Ic rnCb0z3gy2xtSu+Tmj4exgFC47qUsRQ5EwZCymDd7LRsxnauku6ie9m9jTnh0Sk2Yy+y198+vJo an/indnmqOxIsDHAiVxfVQFc0qnNYEhSVKKRCzCGC6sJ3nDCIhPxg9ciad80L1nD9jEFB7kkRRu IteI1jmWX3qwp7xzXaxZ0l0ciilFl+0K0fxIU7YNbdm0IWfV25OJDQcPdlDVY4gGqnkg248Zku1 IEUb45BVWbftJ7Ih4PXxL5XwswGbYeUf77iOoGXOPcPgshfRXNqB7QpY7+dXGTiGxrWmq1uOFAz 7iP77o+3KbfcDoWgYRlNP/dPtmhDXdmZfvUBZQBwtgA== X-Received: by 2002:a17:90b:37ce:b0:353:2972:74a4 with SMTP id 98e67ed59e1d1-353ffaa4138mr479390a91.13.1769491088247; Mon, 26 Jan 2026 21:18:08 -0800 (PST) X-Received: by 2002:a17:90b:37ce:b0:353:2972:74a4 with SMTP id 98e67ed59e1d1-353ffaa4138mr479361a91.13.1769491087913; Mon, 26 Jan 2026 21:18:07 -0800 (PST) From: Ani Sinha To: Paolo Bonzini , Richard Henderson , Eduardo Habkost , "Michael S. Tsirkin" , Marcel Apfelbaum Cc: kraxel@redhat.com, Ani Sinha , qemu-devel@nongnu.org Subject: [PATCH v3 31/33] kvm/clock: add support for confidential guest reset Date: Tue, 27 Jan 2026 10:45:59 +0530 Message-ID: <20260127051612.219475-32-anisinha@redhat.com> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20260127051612.219475-1-anisinha@redhat.com> References: <20260127051612.219475-1-anisinha@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.129.124; envelope-from=anisinha@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_H2=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham 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 development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1769491270054154100 Content-Type: text/plain; charset="utf-8" Confidential guests change the KVM VM file descriptor upon reset and also c= reate new VCPU file descriptors against the new KVM VM file descriptor. We need to save the clock state from kvm before KVM VM file descriptor changes and res= tore it after. Also after VCPU file descriptors changed, we must call KVM_KVMCLOCK_CTRL on the VCPU file descriptor to inform KVM that the VCPU is in paused state. Signed-off-by: Ani Sinha --- hw/i386/kvm/clock.c | 59 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) diff --git a/hw/i386/kvm/clock.c b/hw/i386/kvm/clock.c index aba6842a22..10d34254f0 100644 --- a/hw/i386/kvm/clock.c +++ b/hw/i386/kvm/clock.c @@ -50,6 +50,9 @@ struct KVMClockState { /* whether the 'clock' value was obtained in a host with * reliable KVM_GET_CLOCK */ bool clock_is_reliable; + + NotifierWithReturn kvmclock_vcpufd_change_notifier; + NotifierWithReturn kvmclock_vmfd_change_notifier; }; =20 struct pvclock_vcpu_time_info { @@ -63,6 +66,9 @@ struct pvclock_vcpu_time_info { uint8_t pad[2]; } __attribute__((__packed__)); /* 32 bytes */ =20 +static int kvmclock_set_clock(NotifierWithReturn *notifier, + void *data, Error** errp); + static uint64_t kvmclock_current_nsec(KVMClockState *s) { CPUState *cpu =3D first_cpu; @@ -219,6 +225,54 @@ static void kvmclock_vm_state_change(void *opaque, boo= l running, } } =20 +static int kvmclock_save_clock(NotifierWithReturn *notifier, + void *data, Error** errp) +{ + if (!((VmfdChangeNotifier *)data)->pre) { + return 0; + } + KVMClockState *s =3D container_of(notifier, KVMClockState, + kvmclock_vmfd_change_notifier); + kvm_update_clock(s); + return 0; +} + +static int kvmclock_set_clock(NotifierWithReturn *notifier, + void *data, Error** errp) +{ + struct kvm_clock_data clock_data =3D {}; + CPUState *cpu; + int ret; + KVMClockState *s =3D container_of(notifier, KVMClockState, + kvmclock_vcpufd_change_notifier); + int cap_clock_ctrl =3D kvm_check_extension(kvm_state, KVM_CAP_KVMCLOCK= _CTRL); + + if (!s->clock_is_reliable) { + uint64_t pvclock_via_mem =3D kvmclock_current_nsec(s); + /* saved clock value before vmfd change is not reliable */ + if (pvclock_via_mem) { + s->clock =3D pvclock_via_mem; + } + } + + clock_data.clock =3D s->clock; + ret =3D kvm_vm_ioctl(kvm_state, KVM_SET_CLOCK, &clock_data); + if (ret < 0) { + fprintf(stderr, "KVM_SET_CLOCK failed: %s\n", strerror(-ret)); + abort(); + } + + if (!cap_clock_ctrl) { + return 0; + } + CPU_FOREACH(cpu) { + run_on_cpu(cpu, do_kvmclock_ctrl, RUN_ON_CPU_NULL); + } + + return 0; +} + + static void kvmclock_realize(DeviceState *dev, Error **errp) { KVMClockState *s =3D KVM_CLOCK(dev); @@ -230,7 +284,12 @@ static void kvmclock_realize(DeviceState *dev, Error *= *errp) =20 kvm_update_clock(s); =20 + s->kvmclock_vcpufd_change_notifier.notify =3D kvmclock_set_clock; + s->kvmclock_vmfd_change_notifier.notify =3D kvmclock_save_clock; + qemu_add_vm_change_state_handler(kvmclock_vm_state_change, s); + kvm_vcpufd_add_change_notifier(&s->kvmclock_vcpufd_change_notifier); + kvm_vmfd_add_change_notifier(&s->kvmclock_vmfd_change_notifier); } =20 static bool kvmclock_clock_is_reliable_needed(void *opaque) --=20 2.42.0