From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B240128727D; Fri, 1 May 2026 00:42:13 +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=1777596136; cv=none; b=pMrp62UOYudUvkidFVsAqHNEoLcnUX+EfJ5QkhvCvlRBnMX0nkoHwQ+hDiZ+wh5b/rQKt9FCXBXA/795pOtzgL+iKKVO+cvsclQxkjcES2NeOpe9cP8wycmzu0XMPMIeh1i/AG916jLhfjOqceUhJguIBNnTQGyYnjOwJAtqhiw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777596136; c=relaxed/simple; bh=RL8CMF9VtgQzgIX0JTCcMJjTzHoMPhPoxAA/GgN4+eg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KmgmouWV3u0xGXcltUAdzqzZ0Fn7mRdD8ugu1QWkZyJ6xCkPgPJk2XxvA/sn39WjPgE1GPs7Cq/PYg2w1jmvcsc+2XSdp8I96Lh7r61z3/EDrj5MXPvVcogoiOwFfp8k/T2hbiRaGp7wiW/4UhDC5tHChGye8qvTgKnSfezbgac= 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=AY1QqX63; 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="AY1QqX63" Received: from mrdev.corp.microsoft.com (unknown [40.86.183.173]) by linux.microsoft.com (Postfix) with ESMTPSA id 8717F20B716D; Thu, 30 Apr 2026 17:42:12 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 8717F20B716D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1777596133; bh=kCeRxeZ+DxLmt1F1HSGhNkVBu6/HNQhxryO/F6KU6U0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AY1QqX632IgZ7EMmVmvrRSlMIZIoqZR/YDVPw0qU+MZSpqUne0ynyVENNd1Yu06aI zCcQnVnmp0fqJf93kmCwrjc5Zf1ibhAaUHbUrbvdb7MRNAvxZxozVY0fxyXjkYquXF ipommmfLx8ZgXWQ8zn3dtXwRSXwd28KAPv/q255Q= From: Mukesh R To: hpa@zytor.com, robin.murphy@arm.com, robh@kernel.org, wei.liu@kernel.org, mrathor@linux.microsoft.com, mhklinux@outlook.com, muislam@microsoft.com, namjain@linux.microsoft.com, magnuskulke@linux.microsoft.com, anbelski@linux.microsoft.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arch@vger.kernel.org Cc: kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, longli@microsoft.com, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, joro@8bytes.org, will@kernel.org, lpieralisi@kernel.org, kwilczynski@kernel.org, bhelgaas@google.com, arnd@arndb.de Subject: [PATCH V2 03/11] mshv: Provide a way to get partition id if running in a VMM process Date: Thu, 30 Apr 2026 17:41:49 -0700 Message-ID: <20260501004157.3108202-4-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260501004157.3108202-1-mrathor@linux.microsoft.com> References: <20260501004157.3108202-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Many PCI passthru related hypercalls require partition id of the target guest. Guests are actually managed by MSHV driver and the partition id is only maintained there. Add a field in the partition struct in MSHV driver to save the tgid of the VMM process creating the partition, and add a function there to retrieve partition id if current process is a VMM process. Reviewed-by: Anirudh Rayabharam (Microsoft) Signed-off-by: Mukesh R --- drivers/hv/mshv_root.h | 1 + drivers/hv/mshv_root_main.c | 22 ++++++++++++++++++++++ include/asm-generic/mshyperv.h | 5 +++++ 3 files changed, 28 insertions(+) diff --git a/drivers/hv/mshv_root.h b/drivers/hv/mshv_root.h index 1f086dcb7aa1..a85c24dcc701 100644 --- a/drivers/hv/mshv_root.h +++ b/drivers/hv/mshv_root.h @@ -138,6 +138,7 @@ struct mshv_partition { struct mshv_girq_routing_table __rcu *pt_girq_tbl; u64 isolation_type; + pid_t pt_vmm_tgid; bool import_completed; bool pt_initialized; #if IS_ENABLED(CONFIG_DEBUG_FS) diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c index bd1359eb58dd..02c107458be9 100644 --- a/drivers/hv/mshv_root_main.c +++ b/drivers/hv/mshv_root_main.c @@ -1908,6 +1908,27 @@ mshv_partition_release(struct inode *inode, struct file *filp) return 0; } +/* Given a process tgid, return partition id if it is a VMM process */ +u64 mshv_current_partid(void) +{ + struct mshv_partition *pt; + int i; + u64 ret_ptid = HV_PARTITION_ID_INVALID; + + rcu_read_lock(); + + hash_for_each_rcu(mshv_root.pt_htable, i, pt, pt_hnode) { + if (pt->pt_vmm_tgid == current->tgid) { + ret_ptid = pt->pt_id; + break; + } + } + + rcu_read_unlock(); + return ret_ptid; +} +EXPORT_SYMBOL_GPL(mshv_current_partid); + static int add_partition(struct mshv_partition *partition) { @@ -2073,6 +2094,7 @@ mshv_ioctl_create_partition(void __user *user_arg, struct device *module_dev) goto cleanup_irq_srcu; partition->pt_id = pt_id; + partition->pt_vmm_tgid = current->tgid; ret = add_partition(partition); if (ret) diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h index bf601d67cecb..e8cbc4e3f7ad 100644 --- a/include/asm-generic/mshyperv.h +++ b/include/asm-generic/mshyperv.h @@ -350,6 +350,7 @@ int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id); int hv_call_notify_all_processors_started(void); bool hv_lp_exists(u32 lp_index); int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags); +u64 mshv_current_partid(void); #else /* CONFIG_MSHV_ROOT */ static inline bool hv_root_partition(void) { return false; } @@ -380,6 +381,10 @@ static inline int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u3 { return -EOPNOTSUPP; } +static inline u64 mshv_current_partid(void) +{ + return HV_PARTITION_ID_INVALID; +} #endif /* CONFIG_MSHV_ROOT */ static inline int hv_deposit_memory(u64 partition_id, u64 status) -- 2.51.2.vfs.0.1