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810a521265
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 <dave.hansen@intel.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-4-ltykernel@gmail.com [ wei: fix conflicts with tip ] Signed-off-by: Wei Liu <wei.liu@kernel.org>
105 lines
2.7 KiB
C
105 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Hyper-V Isolation VM interface with paravisor and hypervisor
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*
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* Author:
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* Tianyu Lan <Tianyu.Lan@microsoft.com>
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*/
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#include <linux/hyperv.h>
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#include <linux/types.h>
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#include <linux/bitfield.h>
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#include <linux/slab.h>
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#include <asm/io.h>
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#include <asm/mshyperv.h>
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/*
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* hv_mark_gpa_visibility - Set pages visible to host via hvcall.
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*
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* In Isolation VM, all guest memory is encrypted from host and guest
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* needs to set memory visible to host via hvcall before sharing memory
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* with host.
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*/
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static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
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enum hv_mem_host_visibility visibility)
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{
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struct hv_gpa_range_for_visibility **input_pcpu, *input;
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u16 pages_processed;
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u64 hv_status;
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unsigned long flags;
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/* no-op if partition isolation is not enabled */
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if (!hv_is_isolation_supported())
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return 0;
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if (count > HV_MAX_MODIFY_GPA_REP_COUNT) {
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pr_err("Hyper-V: GPA count:%d exceeds supported:%lu\n", count,
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HV_MAX_MODIFY_GPA_REP_COUNT);
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return -EINVAL;
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}
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local_irq_save(flags);
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input_pcpu = (struct hv_gpa_range_for_visibility **)
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this_cpu_ptr(hyperv_pcpu_input_arg);
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input = *input_pcpu;
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if (unlikely(!input)) {
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local_irq_restore(flags);
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return -EINVAL;
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}
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input->partition_id = HV_PARTITION_ID_SELF;
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input->host_visibility = visibility;
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input->reserved0 = 0;
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input->reserved1 = 0;
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memcpy((void *)input->gpa_page_list, pfn, count * sizeof(*pfn));
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hv_status = hv_do_rep_hypercall(
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HVCALL_MODIFY_SPARSE_GPA_PAGE_HOST_VISIBILITY, count,
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0, input, &pages_processed);
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local_irq_restore(flags);
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if (hv_result_success(hv_status))
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return 0;
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else
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return -EFAULT;
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}
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/*
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* hv_set_mem_host_visibility - Set specified memory visible to host.
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*
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* In Isolation VM, all guest memory is encrypted from host and guest
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* needs to set memory visible to host via hvcall before sharing memory
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* with host. This function works as wrap of hv_mark_gpa_visibility()
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* with memory base and size.
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*/
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int hv_set_mem_host_visibility(unsigned long kbuffer, int pagecount, bool visible)
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{
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enum hv_mem_host_visibility visibility = visible ?
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VMBUS_PAGE_VISIBLE_READ_WRITE : VMBUS_PAGE_NOT_VISIBLE;
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u64 *pfn_array;
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int ret = 0;
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int i, pfn;
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if (!hv_is_isolation_supported() || !hv_hypercall_pg)
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return 0;
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pfn_array = kmalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
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if (!pfn_array)
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return -ENOMEM;
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for (i = 0, pfn = 0; i < pagecount; i++) {
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pfn_array[pfn] = virt_to_hvpfn((void *)kbuffer + i * HV_HYP_PAGE_SIZE);
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pfn++;
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if (pfn == HV_MAX_MODIFY_GPA_REP_COUNT || i == pagecount - 1) {
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ret = hv_mark_gpa_visibility(pfn, pfn_array,
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visibility);
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if (ret)
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goto err_free_pfn_array;
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pfn = 0;
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}
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}
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err_free_pfn_array:
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kfree(pfn_array);
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return ret;
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}
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