Re: [PATCH v3 21/25] KVM: TDX: Add tdx_get_cmd() helper to get and validate sub-ioctl command
From: Huang, Kai <hidden>
Date: 2025-10-24 10:11:57
Also in:
kvm, kvm-riscv, kvmarm, linux-coco, linux-mips, linux-riscv, linuxppc-dev, lkml, loongarch
On Thu, 2025-10-16 at 17:32 -0700, Sean Christopherson wrote:
Add a helper to copy a kvm_tdx_cmd structure from userspace and verify that must-be-zero fields are indeed zero. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Kai Huang <redacted>
quoted hunk ↗ jump to hunk
--- arch/x86/kvm/vmx/tdx.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-)diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 2e2dab89c98f..d5f810435f34 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c@@ -2761,20 +2761,25 @@ static int tdx_td_finalize(struct kvm *kvm, struct kvm_tdx_cmd *cmd) return 0; } +static int tdx_get_cmd(void __user *argp, struct kvm_tdx_cmd *cmd) +{ + if (copy_from_user(cmd, argp, sizeof(*cmd))) + return -EFAULT; + + if (cmd->hw_error) + return -EINVAL;
Nit: to me it's a little bit pity to lose the below comment: /* * Userspace should never set hw_error. It is used to fill * hardware-defined error by the kernel. */