From patchwork Tue Jan 4 19:49:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Raghavendra Rao Ananta X-Patchwork-Id: 12703798 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 2802FC433F5 for ; Tue, 4 Jan 2022 19:51:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:From:Subject:References: Mime-Version:Message-Id:In-Reply-To:Date:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=6fICd5fanUkmFNPLRrQZbATJZ40RUnNnazaWE9kVnTA=; b=sugjtjJeSJgHIC2mN/3oBJQ1GS XM9HAuwmPneJfE6cY4Uk5G/ynMm5bYkRjKIWB5WE4Ojnr7P/QndKzqa8Ve4tmbK1wO8KirgpyQp8l e8E0dw0HoEVeXUmisNhhv8v4VxkSIU0brijswDN5AOVG9VUwZucJWy2Q23OJaso0wXQUEhZ4+pZHK z1kiDckQYJsSrO4N7hopdwM6MmfzKX13L1kt9cZmNcheWZBNU4rc+54H7pOw/UKBhMXj/s13itFhU 57YiaRGtOvHhiNEiLCCqW8y24On5V9q5T6adwB1oRcm/fE4k8vrq5ymbzeyUH3lSZpNv1zSmaWX88 UJmttbFA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n4ppG-00Cfi0-23; Tue, 04 Jan 2022 19:50:30 +0000 Received: from mail-pg1-x549.google.com ([2607:f8b0:4864:20::549]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n4poO-00CfLx-TC for linux-arm-kernel@lists.infradead.org; Tue, 04 Jan 2022 19:49:38 +0000 Received: by mail-pg1-x549.google.com with SMTP id p28-20020a63951c000000b0033f7b94305dso20273502pgd.11 for ; Tue, 04 Jan 2022 11:49:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=Z8f3pbOlFfhJc+MZxj7F3/2ZMbhtOsD2BP3YM7tyFSI=; b=OaSbR2gJ2IXGYHNG7buKj7VOZ4GeQdjTTsbGWOeIcUNX+UJFsEii0dDfyTGsoPxIKb wx8UL7lfUSB21kFvjQEyLl3E6BqGHYLI+Elic6yKmOAqNsqWrB2r+zSmPpF4uLaGQyZY vukjKlc6W07BGNSQgd0GvWKr3TjPRMlVohLF3oUb/hBfj87jwlubT++V0yjMwdC2JSxn ohSNZKVRuRxMUv7IpOQt7LgtleeUnSC40Ulh3+yelQU4udeIldttZVuQ4/lEB/Yz5nFP eZUjGHJTGiIafggw16v3rJ8NP92X239/cHs8ddu1jKMcMoA9KKCV7D4g7AdzGagdG9I6 gtvQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=Z8f3pbOlFfhJc+MZxj7F3/2ZMbhtOsD2BP3YM7tyFSI=; b=tALDSuIeCaM/KjjHzzE/aA9ycdgvFammGyHIkV4mqL3WTRTnoQ9xvvbEgYbHxMfviH ZSyhZy0NULIAiy4SPyTuS94MG2UzzQSLHA5dx56aVuysGv+nsbC5IgJixbgEMckQwfI7 koDUmb/p2/PFdPt0UDKLbsyvHFTLGvLSywZ6+/LdowsI5jRgmKeztywmhhBKw22iAehv /JnqXNqwhnjc4Z5KyIarekSrGESSig58YgQBJUtmfyRqlLfU8699l58uqKUV6aDHvWrm Rn93WFXyvBtW4sTuIMqApyExUHa6aUhcopw/Q9LwqtVj9WHevXdzktkwIq2fR6plem+j osPw== X-Gm-Message-State: AOAM532NWrEf4h7yFaqkI5hcaEG1ulYGeqPYtlTOfGjIxSjrMPdWWVJu 2wzg3YIKiZAtalooFAqd4KgPP/7f8HSN X-Google-Smtp-Source: ABdhPJwRTLWTJz2U+utOgtiR1Vb8LCrr/pZS/a+ivsj8Sv6sdQTy02D1hR10crnPg22DzkZHlLaKsOHvhnxJ X-Received: from rananta-virt.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:1bcc]) (user=rananta job=sendgmr) by 2002:aa7:81ce:0:b0:4bc:d8ec:9748 with SMTP id c14-20020aa781ce000000b004bcd8ec9748mr1389383pfn.29.1641325774964; Tue, 04 Jan 2022 11:49:34 -0800 (PST) Date: Tue, 4 Jan 2022 19:49:10 +0000 In-Reply-To: <20220104194918.373612-1-rananta@google.com> Message-Id: <20220104194918.373612-4-rananta@google.com> Mime-Version: 1.0 References: <20220104194918.373612-1-rananta@google.com> X-Mailer: git-send-email 2.34.1.448.ga2b2bfdf31-goog Subject: [RFC PATCH v3 03/11] KVM: Introduce KVM_CAP_ARM_HVC_FW_REG_BMAP From: Raghavendra Rao Ananta To: Marc Zyngier , Andrew Jones , James Morse , Alexandru Elisei , Suzuki K Poulose Cc: Paolo Bonzini , Catalin Marinas , Will Deacon , Peter Shier , Ricardo Koller , Oliver Upton , Reiji Watanabe , Jing Zhang , Raghavendra Rao Anata , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, kvm@vger.kernel.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220104_114936_993094_60079826 X-CRM114-Status: GOOD ( 14.81 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Introduce the KVM ARM64 capability, KVM_CAP_ARM_HVC_FW_REG_BMAP, to indicate the support for psuedo-firmware bitmap extension. Each of these registers holds a feature-set exposed to the guest in the form of a bitmap. If supported, a simple 'read' of the capability should return the number of psuedo-firmware registers supported. User-space can utilize this to discover the registers. It can further explore or modify the features using the classical GET/SET_ONE_REG interface. Signed-off-by: Raghavendra Rao Ananta --- Documentation/virt/kvm/api.rst | 21 +++++++++++++++++++++ include/uapi/linux/kvm.h | 1 + 2 files changed, 22 insertions(+) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index aeeb071c7688..646176537f2c 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6925,6 +6925,27 @@ indicated by the fd to the VM this is called on. This is intended to support intra-host migration of VMs between userspace VMMs, upgrading the VMM process without interrupting the guest. +7.30 KVM_CAP_ARM_HVC_FW_REG_BMAP +-------------------------------- + +:Architectures: arm64 +:Parameters: None +:Returns: Number of psuedo-firmware registers supported + +This capability indicates that KVM for arm64 supports the psuedo-firmware +register bitmap extension. Each of these registers represent the features +supported by a particular type in the form of a bitmap. By default, these +registers are set with the upper limit of the features that are supported. + +The registers can be accessed via the standard SET_ONE_REG and KVM_GET_ONE_REG +interfaces. The user-space is expected to read the number of these registers +available by reading KVM_CAP_ARM_HVC_FW_REG_BMAP, read the current bitmap +configuration via GET_ONE_REG for each register, and then write back the +desired bitmap of features that it wishes the guest to see via SET_ONE_REG. + +Note that KVM doesn't allow the user-space to modify these registers after +the VM (any of the vCPUs) has started running. + 8. Other capabilities. ====================== diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 1daa45268de2..209b43dbbc3c 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1131,6 +1131,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_EXIT_ON_EMULATION_FAILURE 204 #define KVM_CAP_ARM_MTE 205 #define KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM 206 +#define KVM_CAP_ARM_HVC_FW_REG_BMAP 207 #ifdef KVM_CAP_IRQ_ROUTING