From 810a521265023a1d5c6c081ea2d216bc63d422f5 Mon Sep 17 00:00:00 2001 From: Tianyu Lan Date: Mon, 25 Oct 2021 08:21:08 -0400 Subject: x86/hyperv: Add new hvcall guest address host visibility support Add new hvcall guest address host visibility support to mark memory visible to host. Call it inside set_memory_decrypted /encrypted(). Add HYPERVISOR feature check in the hv_is_isolation_supported() to optimize in non-virtualization environment. Acked-by: Dave Hansen Reviewed-by: Michael Kelley Signed-off-by: Tianyu Lan Link: https://lore.kernel.org/r/20211025122116.264793-4-ltykernel@gmail.com [ wei: fix conflicts with tip ] Signed-off-by: Wei Liu --- arch/x86/hyperv/ivm.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 105 insertions(+) create mode 100644 arch/x86/hyperv/ivm.c (limited to 'arch/x86/hyperv/ivm.c') diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c new file mode 100644 index 000000000000..79e7fb83472a --- /dev/null +++ b/arch/x86/hyperv/ivm.c @@ -0,0 +1,105 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Hyper-V Isolation VM interface with paravisor and hypervisor + * + * Author: + * Tianyu Lan + */ + +#include +#include +#include +#include +#include +#include + +/* + * hv_mark_gpa_visibility - Set pages visible to host via hvcall. + * + * In Isolation VM, all guest memory is encrypted from host and guest + * needs to set memory visible to host via hvcall before sharing memory + * with host. + */ +static int hv_mark_gpa_visibility(u16 count, const u64 pfn[], + enum hv_mem_host_visibility visibility) +{ + struct hv_gpa_range_for_visibility **input_pcpu, *input; + u16 pages_processed; + u64 hv_status; + unsigned long flags; + + /* no-op if partition isolation is not enabled */ + if (!hv_is_isolation_supported()) + return 0; + + if (count > HV_MAX_MODIFY_GPA_REP_COUNT) { + pr_err("Hyper-V: GPA count:%d exceeds supported:%lu\n", count, + HV_MAX_MODIFY_GPA_REP_COUNT); + return -EINVAL; + } + + local_irq_save(flags); + input_pcpu = (struct hv_gpa_range_for_visibility **) + this_cpu_ptr(hyperv_pcpu_input_arg); + input = *input_pcpu; + if (unlikely(!input)) { + local_irq_restore(flags); + return -EINVAL; + } + + input->partition_id = HV_PARTITION_ID_SELF; + input->host_visibility = visibility; + input->reserved0 = 0; + input->reserved1 = 0; + memcpy((void *)input->gpa_page_list, pfn, count * sizeof(*pfn)); + hv_status = hv_do_rep_hypercall( + HVCALL_MODIFY_SPARSE_GPA_PAGE_HOST_VISIBILITY, count, + 0, input, &pages_processed); + local_irq_restore(flags); + + if (hv_result_success(hv_status)) + return 0; + else + return -EFAULT; +} + +/* + * hv_set_mem_host_visibility - Set specified memory visible to host. + * + * In Isolation VM, all guest memory is encrypted from host and guest + * needs to set memory visible to host via hvcall before sharing memory + * with host. This function works as wrap of hv_mark_gpa_visibility() + * with memory base and size. + */ +int hv_set_mem_host_visibility(unsigned long kbuffer, int pagecount, bool visible) +{ + enum hv_mem_host_visibility visibility = visible ? + VMBUS_PAGE_VISIBLE_READ_WRITE : VMBUS_PAGE_NOT_VISIBLE; + u64 *pfn_array; + int ret = 0; + int i, pfn; + + if (!hv_is_isolation_supported() || !hv_hypercall_pg) + return 0; + + pfn_array = kmalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL); + if (!pfn_array) + return -ENOMEM; + + for (i = 0, pfn = 0; i < pagecount; i++) { + pfn_array[pfn] = virt_to_hvpfn((void *)kbuffer + i * HV_HYP_PAGE_SIZE); + pfn++; + + if (pfn == HV_MAX_MODIFY_GPA_REP_COUNT || i == pagecount - 1) { + ret = hv_mark_gpa_visibility(pfn, pfn_array, + visibility); + if (ret) + goto err_free_pfn_array; + pfn = 0; + } + } + + err_free_pfn_array: + kfree(pfn_array); + return ret; +} -- cgit v1.2.3