Commit b2aaf38c authored by Isaku Yamahata's avatar Isaku Yamahata Committed by Paolo Bonzini
Browse files

KVM: TDX: Add place holder for TDX VM specific mem_enc_op ioctl 



KVM_MEMORY_ENCRYPT_OP was introduced for VM-scoped operations specific for
guest state-protected VM.  It defined subcommands for technology-specific
operations under KVM_MEMORY_ENCRYPT_OP.  Despite its name, the subcommands
are not limited to memory encryption, but various technology-specific
operations are defined.  It's natural to repurpose KVM_MEMORY_ENCRYPT_OP
for TDX specific operations and define subcommands.

Add a place holder function for TDX specific VM-scoped ioctl as mem_enc_op.
TDX specific sub-commands will be added to retrieve/pass TDX specific
parameters.  Make mem_enc_ioctl non-optional as it's always filled.

Signed-off-by: default avatarIsaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: default avatarTony Lindgren <tony.lindgren@linux.intel.com>
Signed-off-by: default avatarTony Lindgren <tony.lindgren@linux.intel.com>
Signed-off-by: default avatarRick Edgecombe <rick.p.edgecombe@intel.com>
---
 - Drop the misleading "defined for consistency" line. It's a copy-paste
   error introduced in the earlier patches. Earlier there was padding at
   the end to match struct kvm_sev_cmd size. (Tony)
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent e4aa6f69

arch/x86/include/asm/kvm-x86-ops.h

+1 −1
Original line number Diff line number Diff line
@@ -125,7 +125,7 @@ KVM_X86_OP(leave_smm) 
KVM_X86_OP(enable_smi_window)

#endif

KVM_X86_OP_OPTIONAL(dev_get_attr)

KVM_X86_OP_OPTIONAL(mem_enc_ioctl)

KVM_X86_OP(mem_enc_ioctl)

KVM_X86_OP_OPTIONAL(mem_enc_register_region)

KVM_X86_OP_OPTIONAL(mem_enc_unregister_region)

KVM_X86_OP_OPTIONAL(vm_copy_enc_context_from)

arch/x86/include/uapi/asm/kvm.h

+23 −0
Original line number Diff line number Diff line
@@ -927,4 +927,27 @@ struct kvm_hyperv_eventfd { 
#define KVM_X86_SNP_VM		4

#define KVM_X86_TDX_VM		5



/* Trust Domain eXtension sub-ioctl() commands. */

enum kvm_tdx_cmd_id {

	KVM_TDX_CMD_NR_MAX,

};



struct kvm_tdx_cmd {

	/* enum kvm_tdx_cmd_id */

	__u32 id;

	/* flags for sub-commend. If sub-command doesn't use this, set zero. */

	__u32 flags;

	/*

	 * data for each sub-command. An immediate or a pointer to the actual

	 * data in process virtual address.  If sub-command doesn't use it,

	 * set zero.

	 */

	__u64 data;

	/*

	 * Auxiliary error code.  The sub-command may return TDX SEAMCALL

	 * status code in addition to -Exxx.

	 */

	__u64 hw_error;

};



#endif /* _ASM_X86_KVM_H */

arch/x86/kvm/vmx/main.c

+10 −0
Original line number Diff line number Diff line
@@ -41,6 +41,14 @@ static __init int vt_hardware_setup(void) 
	return 0;

}



static int vt_mem_enc_ioctl(struct kvm *kvm, void __user *argp)

{

	if (!is_td(kvm))

		return -ENOTTY;



	return tdx_vm_ioctl(kvm, argp);

}



#define VMX_REQUIRED_APICV_INHIBITS				\

	(BIT(APICV_INHIBIT_REASON_DISABLED) |			\

	 BIT(APICV_INHIBIT_REASON_ABSENT) |			\
@@ -193,6 +201,8 @@ struct kvm_x86_ops vt_x86_ops __initdata = { 
	.vcpu_deliver_sipi_vector = kvm_vcpu_deliver_sipi_vector,



	.get_untagged_addr = vmx_get_untagged_addr,



	.mem_enc_ioctl = vt_mem_enc_ioctl,

};



struct kvm_x86_init_ops vt_init_ops __initdata = {

arch/x86/kvm/vmx/tdx.c

+32 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
#include <asm/cpufeature.h>

#include <asm/tdx.h>

#include "capabilities.h"

#include "x86_ops.h"

#include "tdx.h"



#pragma GCC poison to_vmx
@@ -42,6 +43,37 @@ static __always_inline struct vcpu_tdx *to_tdx(struct kvm_vcpu *vcpu) 
	return container_of(vcpu, struct vcpu_tdx, vcpu);

}



int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)

{

	struct kvm_tdx_cmd tdx_cmd;

	int r;



	if (copy_from_user(&tdx_cmd, argp, sizeof(struct kvm_tdx_cmd)))

		return -EFAULT;



	/*

	 * Userspace should never set hw_error. It is used to fill

	 * hardware-defined error by the kernel.

	 */

	if (tdx_cmd.hw_error)

		return -EINVAL;



	mutex_lock(&kvm->lock);



	switch (tdx_cmd.id) {

	default:

		r = -EINVAL;

		goto out;

	}



	if (copy_to_user(argp, &tdx_cmd, sizeof(struct kvm_tdx_cmd)))

		r = -EFAULT;



out:

	mutex_unlock(&kvm->lock);

	return r;

}



static int tdx_online_cpu(unsigned int cpu)

{

	unsigned long flags;

arch/x86/kvm/vmx/x86_ops.h

+6 −0
Original line number Diff line number Diff line
@@ -121,4 +121,10 @@ void vmx_cancel_hv_timer(struct kvm_vcpu *vcpu); 
#endif

void vmx_setup_mce(struct kvm_vcpu *vcpu);



#ifdef CONFIG_KVM_INTEL_TDX

int tdx_vm_ioctl(struct kvm *kvm, void __user *argp);

#else

static inline int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) { return -EOPNOTSUPP; }

#endif



#endif /* __KVM_X86_VMX_X86_OPS_H */