From nobody Wed Oct 1 23:34:12 2025 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 90261258EE0; Fri, 26 Sep 2025 16:23:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758903806; cv=none; b=n0iDIuEZ1HesfKg6DAgjlyh7D2LXa+tY+5JM28yuuKkkoGCbC7xu+WmIAbhRbcsB1gDZC4WN3z2DNihJ3ThcODtK0R4LF1NeDs6EbC//Srq8LU/meAa9yo27aB3uuuprZnKAzecXD6E/4w34Z7Sxp5coYcEBkMfMamF6SNISQaM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758903806; c=relaxed/simple; bh=FsDdKwCMqTABgOU+0KZfVkac48eymIJV4GoA81z0p+0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=K8Bb8FgxxQViNZfAXA6ZBJ+MTvAL3amOvp6pFOuPjIye7Vi4VOBlZ5I8poVo5qMSPQ1Q2ufEsjHjWk4j3/RzPqnTd4ZDq/2BllsxiziH8QyXo0Cvp/TwQ8/JLtbgnG3Vc/JOY6uy+NMuEN2nSfNFxGNVxKoGkNt4OYyaCDQXvkM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=rKuv+xwQ; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="rKuv+xwQ" Received: by linux.microsoft.com (Postfix, from userid 1032) id CA5C12124F6F; Fri, 26 Sep 2025 09:23:18 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com CA5C12124F6F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1758903798; bh=tWfyl8/jJ38C1AnsDNtGxPJggw4ujw1MyZ8mJDXpanU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rKuv+xwQSdDDosAcXNYnh0v2B6Nvhl1MiIC8Odl/F+JKzb95pbqDmqSs72K9fAt3+ AILQHo1xcfHXxdWKw5aX3enDpqk05M9mtk0J9r5/mhA6sCaDkYbmrRyOXKBpFkggGZ 3MZksK+YIJrE8N6qO1YG8vkPZcWbwzN2WnnCxms4= From: Nuno Das Neves To: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, prapal@linux.microsoft.com, easwar.hariharan@linux.microsoft.com, tiala@microsoft.com, anirudh@anirudhrb.com, paekkaladevi@linux.microsoft.com, skinsburskii@linux.microsoft.com Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, Nuno Das Neves Subject: [PATCH v4 3/5] mshv: Get the vmm capabilities offered by the hypervisor Date: Fri, 26 Sep 2025 09:23:13 -0700 Message-Id: <1758903795-18636-4-git-send-email-nunodasneves@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1758903795-18636-1-git-send-email-nunodasneves@linux.microsoft.com> References: <1758903795-18636-1-git-send-email-nunodasneves@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Purna Pavan Chandra Aekkaladevi Some hypervisor APIs are gated by feature bits in the "vmm capabilities" partition property. Store the capabilities on mshv_root module init, using HVCALL_GET_PARTITION_PROPERTY_EX. This is not supported on all hypervisors. In that case, just set the capabilities to 0 and proceed as normal. Signed-off-by: Purna Pavan Chandra Aekkaladevi Signed-off-by: Nuno Das Neves Reviewed-by: Praveen K Paladugu Reviewed-by: Easwar Hariharan Reviewed-by: Tianyu Lan --- drivers/hv/mshv_root.h | 1 + drivers/hv/mshv_root_main.c | 17 +++++++++++++++++ 2 files changed, 18 insertions(+) diff --git a/drivers/hv/mshv_root.h b/drivers/hv/mshv_root.h index 4aeb03bea6b6..0cb1e2589fe1 100644 --- a/drivers/hv/mshv_root.h +++ b/drivers/hv/mshv_root.h @@ -178,6 +178,7 @@ struct mshv_root { struct hv_synic_pages __percpu *synic_pages; spinlock_t pt_ht_lock; DECLARE_HASHTABLE(pt_htable, MSHV_PARTITIONS_HASH_BITS); + struct hv_partition_property_vmm_capabilities vmm_caps; }; =20 /* diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c index 24df47726363..e199770ecdfa 100644 --- a/drivers/hv/mshv_root_main.c +++ b/drivers/hv/mshv_root_main.c @@ -2201,6 +2201,21 @@ static int __init mshv_root_partition_init(struct de= vice *dev) return err; } =20 +static void mshv_init_vmm_caps(struct device *dev) +{ + /* + * HVCALL_GET_PARTITION_PROPERTY_EX or HV_PARTITION_PROPERTY_VMM_CAPABILI= TIES + * may not be supported. Leave them as 0 in that case. + */ + if (hv_call_get_partition_property_ex(HV_PARTITION_ID_SELF, + HV_PARTITION_PROPERTY_VMM_CAPABILITIES, + 0, &mshv_root.vmm_caps, + sizeof(mshv_root.vmm_caps))) + dev_warn(dev, "Unable to get VMM capabilities\n"); + + dev_dbg(dev, "vmm_caps=3D0x%llx\n", mshv_root.vmm_caps.as_uint64[0]); +} + static int __init mshv_parent_partition_init(void) { int ret; @@ -2253,6 +2268,8 @@ static int __init mshv_parent_partition_init(void) if (ret) goto remove_cpu_state; =20 + mshv_init_vmm_caps(dev); + ret =3D mshv_irqfd_wq_init(); if (ret) goto exit_partition; --=20 2.34.1