1 #ifndef __LINUX_KVM_PARA_H 2 #define __LINUX_KVM_PARA_H 3 4 /* 5 * Guest OS interface for KVM paravirtualization 6 * 7 * Note: this interface is totally experimental, and is certain to change 8 * as we make progress. 9 */ 10 11 /* 12 * Per-VCPU descriptor area shared between guest and host. Writable to 13 * both guest and host. Registered with the host by the guest when 14 * a guest acknowledges paravirtual mode. 15 * 16 * NOTE: all addresses are guest-physical addresses (gpa), to make it 17 * easier for the hypervisor to map between the various addresses. 18 */ 19 struct kvm_vcpu_para_state { 20 /* 21 * API version information for compatibility. If there's any support 22 * mismatch (too old host trying to execute too new guest) then 23 * the host will deny entry into paravirtual mode. Any other 24 * combination (new host + old guest and new host + new guest) 25 * is supposed to work - new host versions will support all old 26 * guest API versions. 27 */ 28 u32 guest_version; 29 u32 host_version; 30 u32 size; 31 u32 ret; 32 33 /* 34 * The address of the vm exit instruction (VMCALL or VMMCALL), 35 * which the host will patch according to the CPU model the 36 * VM runs on: 37 */ 38 u64 hypercall_gpa; 39 40 } __attribute__ ((aligned(PAGE_SIZE))); 41 42 #define KVM_PARA_API_VERSION 1 43 44 /* 45 * This is used for an RDMSR's ECX parameter to probe for a KVM host. 46 * Hopefully no CPU vendor will use up this number. This is placed well 47 * out of way of the typical space occupied by CPU vendors' MSR indices, 48 * and we think (or at least hope) it wont be occupied in the future 49 * either. 50 */ 51 #define MSR_KVM_API_MAGIC 0x87655678 52 53 #define KVM_EINVAL 1 54 55 #endif 56