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From: shuo.a.liu@intel.com
To: linux-kernel@vger.kernel.org, x86@kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"H . Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	Yu Wang <yu1.wang@intel.com>,
	Reinette Chatre <reinette.chatre@intel.com>,
	Shuo Liu <shuo.a.liu@intel.com>, Zhi Wang <zhi.a.wang@intel.com>,
	Zhenyu Wang <zhenyuw@linux.intel.com>
Subject: [PATCH v6 17/18] virt: acrn: Introduce an interface for Service VM to control vCPU
Date: Tue,  1 Dec 2020 17:38:52 +0800	[thread overview]
Message-ID: <20201201093853.12070-18-shuo.a.liu@intel.com> (raw)
In-Reply-To: <20201201093853.12070-1-shuo.a.liu@intel.com>

From: Shuo Liu <shuo.a.liu@intel.com>

ACRN supports partition mode to achieve real-time requirements. In
partition mode, a CPU core can be dedicated to a vCPU of User VM. The
local APIC of the dedicated CPU core can be passthrough to the User VM.
The Service VM controls the assignment of the CPU cores.

Introduce an interface for the Service VM to remove the control of CPU
core from hypervisor perspective so that the CPU core can be a dedicated
CPU core of User VM.

Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Yu Wang <yu1.wang@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/virt/acrn/hsm.c       | 48 +++++++++++++++++++++++++++++++++++
 drivers/virt/acrn/hypercall.h | 14 ++++++++++
 2 files changed, 62 insertions(+)

diff --git a/drivers/virt/acrn/hsm.c b/drivers/virt/acrn/hsm.c
index b8c1255247e5..1bee07a9d3f5 100644
--- a/drivers/virt/acrn/hsm.c
+++ b/drivers/virt/acrn/hsm.c
@@ -9,6 +9,7 @@
  *	Yakui Zhao <yakui.zhao@intel.com>
  */
 
+#include <linux/cpu.h>
 #include <linux/io.h>
 #include <linux/mm.h>
 #include <linux/module.h>
@@ -347,6 +348,52 @@ static int acrn_dev_release(struct inode *inode, struct file *filp)
 	return 0;
 }
 
+static ssize_t remove_cpu_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	u64 cpu, lapicid;
+	int ret;
+
+	if (kstrtoull(buf, 0, &cpu) < 0)
+		return -EINVAL;
+
+	if (cpu >= num_possible_cpus() || cpu == 0 || !cpu_is_hotpluggable(cpu))
+		return -EINVAL;
+
+	if (cpu_online(cpu))
+		remove_cpu(cpu);
+
+	lapicid = cpu_data(cpu).apicid;
+	dev_dbg(dev, "Try to remove cpu %lld with lapicid %lld\n", cpu, lapicid);
+	ret = hcall_sos_remove_cpu(lapicid);
+	if (ret < 0) {
+		dev_err(dev, "Failed to remove cpu %lld!\n", cpu);
+		goto fail_remove;
+	}
+
+	return count;
+
+fail_remove:
+	add_cpu(cpu);
+	return ret;
+}
+static DEVICE_ATTR_WO(remove_cpu);
+
+static struct attribute *acrn_attrs[] = {
+	&dev_attr_remove_cpu.attr,
+	NULL
+};
+
+static struct attribute_group acrn_attr_group = {
+	.attrs = acrn_attrs,
+};
+
+static const struct attribute_group *acrn_attr_groups[] = {
+	&acrn_attr_group,
+	NULL
+};
+
 static const struct file_operations acrn_fops = {
 	.owner		= THIS_MODULE,
 	.open		= acrn_dev_open,
@@ -358,6 +405,7 @@ struct miscdevice acrn_dev = {
 	.minor	= MISC_DYNAMIC_MINOR,
 	.name	= "acrn_hsm",
 	.fops	= &acrn_fops,
+	.groups	= acrn_attr_groups,
 };
 
 static int __init hsm_init(void)
diff --git a/drivers/virt/acrn/hypercall.h b/drivers/virt/acrn/hypercall.h
index e640632366f0..0cfad05bd1a9 100644
--- a/drivers/virt/acrn/hypercall.h
+++ b/drivers/virt/acrn/hypercall.h
@@ -13,6 +13,9 @@
 
 #define HC_ID 0x80UL
 
+#define HC_ID_GEN_BASE			0x0UL
+#define HC_SOS_REMOVE_CPU		_HC_ID(HC_ID, HC_ID_GEN_BASE + 0x01)
+
 #define HC_ID_VM_BASE			0x10UL
 #define HC_CREATE_VM			_HC_ID(HC_ID, HC_ID_VM_BASE + 0x00)
 #define HC_DESTROY_VM			_HC_ID(HC_ID, HC_ID_VM_BASE + 0x01)
@@ -42,6 +45,17 @@
 #define HC_ID_PM_BASE			0x80UL
 #define HC_PM_GET_CPU_STATE		_HC_ID(HC_ID, HC_ID_PM_BASE + 0x00)
 
+/**
+ * hcall_sos_remove_cpu() - Remove a vCPU of Service VM
+ * @cpu: The vCPU to be removed
+ *
+ * Return: 0 on success, <0 on failure
+ */
+static inline long hcall_sos_remove_cpu(u64 cpu)
+{
+	return acrn_hypercall1(HC_SOS_REMOVE_CPU, cpu);
+}
+
 /**
  * hcall_create_vm() - Create a User VM
  * @vminfo:	Service VM GPA of info of User VM creation
-- 
2.28.0


  parent reply	other threads:[~2020-12-01  9:42 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-01  9:38 [PATCH v6 00/18] HSM driver for ACRN hypervisor shuo.a.liu
2020-12-01  9:38 ` [PATCH v6 01/18] docs: acrn: Introduce ACRN shuo.a.liu
2020-12-08 11:52   ` Borislav Petkov
2020-12-09  1:36     ` Shuo A Liu
2020-12-01  9:38 ` [PATCH v6 02/18] x86/acrn: Introduce acrn_{setup, remove}_intr_handler() shuo.a.liu
2020-12-01  9:38 ` [PATCH v6 03/18] x86/acrn: Introduce acrn_cpuid_base() and hypervisor feature bits shuo.a.liu
2020-12-01  9:38 ` [PATCH v6 04/18] x86/acrn: Introduce hypercall interfaces shuo.a.liu
2020-12-30 17:33   ` Borislav Petkov
2021-01-06  7:52     ` Shuo A Liu
2020-12-01  9:38 ` [PATCH v6 05/18] virt: acrn: Introduce ACRN HSM basic driver shuo.a.liu
2020-12-01  9:38 ` [PATCH v6 06/18] virt: acrn: Introduce VM management interfaces shuo.a.liu
2020-12-01 10:09   ` Greg Kroah-Hartman
2020-12-02  2:14     ` Shuo A Liu
2020-12-15  9:52       ` Shuo A Liu
2020-12-15 10:00         ` Greg Kroah-Hartman
2020-12-15 10:02           ` Shuo A Liu
2021-01-05 14:03             ` Greg Kroah-Hartman
2021-01-06  7:56               ` Shuo A Liu
2020-12-01  9:38 ` [PATCH v6 07/18] virt: acrn: Introduce an ioctl to set vCPU registers state shuo.a.liu
2020-12-01  9:38 ` [PATCH v6 08/18] virt: acrn: Introduce EPT mapping management shuo.a.liu
2020-12-01  9:38 ` [PATCH v6 09/18] virt: acrn: Introduce I/O request management shuo.a.liu
2020-12-01  9:38 ` [PATCH v6 10/18] virt: acrn: Introduce PCI configuration space PIO accesses combiner shuo.a.liu
2020-12-01  9:38 ` [PATCH v6 11/18] virt: acrn: Introduce interfaces for PCI device passthrough shuo.a.liu
2020-12-01  9:38 ` [PATCH v6 12/18] virt: acrn: Introduce interrupt injection interfaces shuo.a.liu
2020-12-01  9:38 ` [PATCH v6 13/18] virt: acrn: Introduce interfaces to query C-states and P-states allowed by hypervisor shuo.a.liu
2020-12-01  9:38 ` [PATCH v6 14/18] virt: acrn: Introduce I/O ranges operation interfaces shuo.a.liu
2020-12-01  9:38 ` [PATCH v6 15/18] virt: acrn: Introduce ioeventfd shuo.a.liu
2020-12-01  9:38 ` [PATCH v6 16/18] virt: acrn: Introduce irqfd shuo.a.liu
2020-12-01  9:38 ` shuo.a.liu [this message]
2020-12-01  9:38 ` [PATCH v6 18/18] sample/acrn: Introduce a sample of HSM ioctl interface usage shuo.a.liu

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