Re: [PATCH v11 08/21] virt: geniezone: Add vcpu support

On Wed, May 29, 2024 at 04:42:26PM +0800, Liju-clr Chen wrote:

From: Yi-De Wu <redacted>

From: "Yingshiuan Pan" <redacted>

nit: I think there should be at most one From line,
     denoting the author of the patch. Based on the Signed-off-by
     lines I assume that is Yingshiuan Pan.

     If there are multiple authors perhaps
     the Co-developed-by tag should be used below.

     And on that note, it's not clear to me what the significance
     of the Signed-off-by lines, other than that of
     Yingshiuan Pan (presumed author) and Liju Chen (sender) are.
     I'd suggest deleting them unless they are
     accompanied by Co-developed-by tags.

     And, lastly, the sender's signed-off-by line should come last.

     See: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#sign-your-work-the-developer-s-certificate-of-origin

VMM use this interface to create vcpu instance which is a fd, and this
fd will be for any vcpu operations, such as setting vcpu registers and
accepts the most important ioctl GZVM_VCPU_RUN which requests GenieZone
hypervisor to do context switch to execute VM's vcpu context.

Signed-off-by: Yingshiuan Pan <redacted>
Signed-off-by: Jerry Wang <redacted>
Signed-off-by: kevenny hsieh <redacted>
Signed-off-by: Liju Chen <redacted>
Signed-off-by: Yi-De Wu <redacted>

...

nit: It's not clear to me that sysreg.h needs to be included in this file.

+#include <linux/anon_inodes.h>
+#include <linux/device.h>
+#include <linux/file.h>
+#include <linux/mm.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/soc/mediatek/gzvm_drv.h>
+
+/* maximum size needed for holding an integer */
+#define ITOA_MAX_LEN 12
+
+static long gzvm_vcpu_update_one_reg(struct gzvm_vcpu *vcpu,
+				     void __user *argp,
+				     bool is_write)
+{
+	struct gzvm_one_reg reg;
+	void __user *reg_addr;
+	u64 data = 0;
+	u64 reg_size;
+	long ret;
+
+	if (copy_from_user(&reg, argp, sizeof(reg)))
+		return -EFAULT;
+
+	reg_addr = (void __user *)reg.addr;

nit: Perhaps u64_to_user_ptr() is appropriate here.

     Also in gzvm_vm_ioctl_create_device() in patch 09/21.

+	reg_size = (reg.id & GZVM_REG_SIZE_MASK) >> GZVM_REG_SIZE_SHIFT;
+	reg_size = BIT(reg_size);
+
+	if (reg_size != 1 && reg_size != 2 && reg_size != 4 && reg_size != 8)
+		return -EINVAL;
+
+	if (is_write) {
+		/* GZ hypervisor would filter out invalid vcpu register access */
+		if (copy_from_user(&data, reg_addr, reg_size))
+			return -EFAULT;
+	} else {
+		return -EOPNOTSUPP;
+	}
+
+	ret = gzvm_arch_vcpu_update_one_reg(vcpu, reg.id, is_write, &data);
+
+	if (ret)
+		return ret;
+
+	return 0;
+}

...