Add GHCB management functionality similar to the ucall management. Allows for selftest vCPUs to acquire GHCBs for their usage.
Cc: Vishal Annapurve vannapurve@google.com Cc: Ackerley Tng ackerleytng@google.com Cc: Paolo Bonzini pbonzini@redhat.com Cc: Claudio Imbrenda imbrenda@linux.ibm.com Cc: Sean Christopherson seanjc@google.com Cc: Carlos Bilbao carlos.bilbao@amd.com Cc: Tom Lendacky thomas.lendacky@amd.com Cc: Michael Roth michael.roth@amd.com Cc: kvm@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Signed-off-by: Peter Gonda pgonda@google.com --- .../selftests/kvm/include/x86_64/sev.h | 2 + .../selftests/kvm/lib/x86_64/processor.c | 8 ++ tools/testing/selftests/kvm/lib/x86_64/sev.c | 77 +++++++++++++++++++ 3 files changed, 87 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/x86_64/sev.h b/tools/testing/selftests/kvm/include/x86_64/sev.h index 8a1bf88474c9..bfd481707f67 100644 --- a/tools/testing/selftests/kvm/include/x86_64/sev.h +++ b/tools/testing/selftests/kvm/include/x86_64/sev.h @@ -27,6 +27,8 @@ enum sev_guest_state {
#define GHCB_MSR_TERM_REQ 0x100
+int ghcb_nr_pages_required(uint64_t page_size); + void sev_vm_launch(struct kvm_vm *vm, uint32_t policy); void sev_vm_launch_measure(struct kvm_vm *vm, uint8_t *measurement); void sev_vm_launch_finish(struct kvm_vm *vm); diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index 49288fe10cd3..fd94a1bd82c9 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -584,6 +584,14 @@ void kvm_arch_vm_post_create(struct kvm_vm *vm) sev_es_vm_init(vm); }
+int kvm_arch_vm_additional_pages_required(struct vm_shape shape, uint64_t page_size) +{ + if (shape.subtype == VM_SUBTYPE_SEV_ES) + return ghcb_nr_pages_required(page_size); + + return 0; +} + void vcpu_arch_set_entry_point(struct kvm_vcpu *vcpu, void *guest_code) { struct kvm_regs regs; diff --git a/tools/testing/selftests/kvm/lib/x86_64/sev.c b/tools/testing/selftests/kvm/lib/x86_64/sev.c index e248d3364b9c..27ae1d3b1355 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/sev.c +++ b/tools/testing/selftests/kvm/lib/x86_64/sev.c @@ -4,6 +4,80 @@ #include <stdbool.h>
#include "sev.h" +#include "linux/bitmap.h" +#include "svm.h" +#include "svm_util.h" + +struct ghcb_entry { + struct ghcb ghcb; + + /* Guest physical address of this GHCB. */ + void *gpa; + + /* Host virtual address of this struct. */ + struct ghcb_entry *hva; +}; + +struct ghcb_header { + struct ghcb_entry ghcbs[KVM_MAX_VCPUS]; + DECLARE_BITMAP(in_use, KVM_MAX_VCPUS); +}; + +static struct ghcb_header *ghcb_pool; + +int ghcb_nr_pages_required(uint64_t page_size) +{ + return align_up(sizeof(struct ghcb_header), page_size) / page_size; +} + +void ghcb_init(struct kvm_vm *vm) +{ + struct ghcb_header *hdr; + struct ghcb_entry *entry; + vm_vaddr_t vaddr; + int i; + + vaddr = vm_vaddr_alloc_shared(vm, sizeof(*hdr), KVM_UTIL_MIN_VADDR, + MEM_REGION_DATA); + hdr = (struct ghcb_header *)addr_gva2hva(vm, vaddr); + memset(hdr, 0, sizeof(*hdr)); + + for (i = 0; i < KVM_MAX_VCPUS; ++i) { + entry = &hdr->ghcbs[i]; + entry->hva = entry; + entry->gpa = addr_hva2gpa(vm, &entry->ghcb); + } + + write_guest_global(vm, ghcb_pool, (struct ghcb_header *)vaddr); +} + +static struct ghcb_entry *ghcb_alloc(void) +{ + return &ghcb_pool->ghcbs[0]; + struct ghcb_entry *entry; + int i; + + if (!ghcb_pool) + goto ucall_failed; + + for (i = 0; i < KVM_MAX_VCPUS; ++i) { + if (!test_and_set_bit(i, ghcb_pool->in_use)) { + entry = &ghcb_pool->ghcbs[i]; + memset(&entry->ghcb, 0, sizeof(entry->ghcb)); + return entry; + } + } + +ucall_failed: + return NULL; +} + +static void ghcb_free(struct ghcb_entry *entry) +{ + /* Beware, here be pointer arithmetic. */ + clear_bit(entry - ghcb_pool->ghcbs, ghcb_pool->in_use); +} +
/* * sparsebit_next_clear() can return 0 if [x, 2**64-1] are all set, and the @@ -44,6 +118,9 @@ void sev_vm_launch(struct kvm_vm *vm, uint32_t policy) struct kvm_sev_guest_status status; int ctr;
+ if (policy & SEV_POLICY_ES) + ghcb_init(vm); + vm_sev_ioctl(vm, KVM_SEV_LAUNCH_START, &launch_start); vm_sev_ioctl(vm, KVM_SEV_GUEST_STATUS, &status);