Commit 4b7d440d authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

Merge tag 'kvm-x86-fixes-6.16-rc7' of https://github.com/kvm-x86/linux into HEAD 

KVM TDX fixes for 6.16

 - Fix a formatting goof in the TDX documentation.

 - Reject KVM_SET_TSC_KHZ for guests with a protected TSC (currently only TDX).

 - Ensure struct kvm_tdx_capabilities fields that are not explicitly set by KVM
   are zeroed.
parents ed302854 b8be70ec

Documentation/virt/kvm/api.rst

+9 −2
Original line number Diff line number Diff line
@@ -2008,6 +2008,13 @@ If the KVM_CAP_VM_TSC_CONTROL capability is advertised, this can also 
be used as a vm ioctl to set the initial tsc frequency of subsequently

created vCPUs.



For TSC protected Confidential Computing (CoCo) VMs where TSC frequency

is configured once at VM scope and remains unchanged during VM's

lifetime, the vm ioctl should be used to configure the TSC frequency

and the vcpu ioctl is not supported.



Example of such CoCo VMs: TDX guests.



4.56 KVM_GET_TSC_KHZ

--------------------

arch/x86/kvm/vmx/tdx.c

+4 −3
Original line number Diff line number Diff line
@@ -2269,25 +2269,26 @@ static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd) 
	const struct tdx_sys_info_td_conf *td_conf = &tdx_sysinfo->td_conf;

	struct kvm_tdx_capabilities __user *user_caps;

	struct kvm_tdx_capabilities *caps = NULL;

	u32 nr_user_entries;

	int ret = 0;



	/* flags is reserved for future use */

	if (cmd->flags)

		return -EINVAL;



	caps = kmalloc(sizeof(*caps) +

	caps = kzalloc(sizeof(*caps) +

		       sizeof(struct kvm_cpuid_entry2) * td_conf->num_cpuid_config,

		       GFP_KERNEL);

	if (!caps)

		return -ENOMEM;



	user_caps = u64_to_user_ptr(cmd->data);

	if (copy_from_user(caps, user_caps, sizeof(*caps))) {

	if (get_user(nr_user_entries, &user_caps->cpuid.nent)) {

		ret = -EFAULT;

		goto out;

	}



	if (caps->cpuid.nent < td_conf->num_cpuid_config) {

	if (nr_user_entries < td_conf->num_cpuid_config) {

		ret = -E2BIG;

		goto out;

	}

arch/x86/kvm/x86.c

+4 −0
Original line number Diff line number Diff line
@@ -6188,6 +6188,10 @@ long kvm_arch_vcpu_ioctl(struct file *filp, 
		u32 user_tsc_khz;



		r = -EINVAL;



		if (vcpu->arch.guest_tsc_protected)

			goto out;



		user_tsc_khz = (u32)arg;



		if (kvm_caps.has_tsc_control &&