The command is used for encrypting guest memory region. For more information see [1], section 6.2
[1] http://support.amd.com/TechDocs/55766_SEV-KM%20API_Spec.pdf Signed-off-by: Brijesh Singh <brijesh.si...@amd.com> --- arch/x86/kvm/svm.c | 126 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 126 insertions(+) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 0b6da4a..c78bdc6 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -35,6 +35,8 @@ #include <linux/trace_events.h> #include <linux/slab.h> #include <linux/ccp-psp.h> +#include <linux/pagemap.h> +#include <linux/swap.h> #include <asm/apic.h> #include <asm/perf_event.h> @@ -263,6 +265,8 @@ static unsigned long *sev_asid_bitmap; #define svm_sev_guest() (svm->vcpu.kvm->arch.sev_info.handle) #define svm_sev_ref_count() (svm->vcpu.kvm->arch.sev_info.ref_count) +#define __sev_page_pa(x) ((page_to_pfn(x) << PAGE_SHIFT) | sme_me_mask) + static int sev_asid_new(void); static void sev_asid_free(int asid); static void sev_deactivate_handle(unsigned int handle); @@ -5376,6 +5380,123 @@ err_1: return ret; } +static int sev_pre_update(struct page **pages, unsigned long uaddr, int npages) +{ + int pinned; + + /* pin the user virtual address */ + down_read(¤t->mm->mmap_sem); + pinned = get_user_pages(uaddr, npages, 1, 0, pages, NULL); + up_read(¤t->mm->mmap_sem); + if (pinned != npages) { + printk(KERN_ERR "SEV: failed to pin %d pages (got %d)\n", + npages, pinned); + goto err; + } + + return 0; +err: + if (pinned > 0) + release_pages(pages, pinned, 0); + return 1; +} + +static int sev_launch_update(struct kvm *kvm, + struct kvm_sev_launch_update __user *arg, + int *psp_ret) +{ + int first, last; + struct page **inpages; + int ret, nr_pages; + unsigned long uaddr, ulen; + int i, buffer_len, len, offset; + struct kvm_sev_launch_update params; + struct psp_data_launch_update *update; + + /* Get the parameters from the user */ + if (copy_from_user(¶ms, arg, sizeof(*arg))) + return -EFAULT; + + uaddr = params.address; + ulen = params.length; + + /* Get number of pages */ + first = (uaddr & PAGE_MASK) >> PAGE_SHIFT; + last = ((uaddr + ulen - 1) & PAGE_MASK) >> PAGE_SHIFT; + nr_pages = (last - first + 1); + + /* allocate the buffers */ + buffer_len = sizeof(*update); + update = kzalloc(buffer_len, GFP_KERNEL); + if (!update) + return -ENOMEM; + + ret = -ENOMEM; + inpages = kzalloc(nr_pages * sizeof(struct page *), GFP_KERNEL); + if (!inpages) + goto err_1; + + ret = sev_pre_update(inpages, uaddr, nr_pages); + if (ret) + goto err_2; + + /* the array of pages returned by get_user_pages() is a page-aligned + * memory. Since the user buffer is probably not page-aligned, we need + * to calculate the offset within a page for first update entry. + */ + offset = uaddr & (PAGE_SIZE - 1); + len = min_t(size_t, (PAGE_SIZE - offset), ulen); + ulen -= len; + + /* update first page - + * special care need to be taken for the first page because we might + * be dealing with offset within the page + */ + update->hdr.buffer_len = buffer_len; + update->handle = kvm_sev_handle(); + update->length = len; + update->address = __sev_page_pa(inpages[0]) + offset; + clflush_cache_range(page_address(inpages[0]), PAGE_SIZE); + ret = psp_guest_launch_update(update, 5, psp_ret); + if (ret) { + printk(KERN_ERR "SEV: LAUNCH_UPDATE addr %#llx len %d " + "ret=%d (%#010x)\n", update->address, + update->length, ret, *psp_ret); + goto err_3; + } + + /* update remaining pages */ + for (i = 1; i < nr_pages; i++) { + + len = min_t(size_t, PAGE_SIZE, ulen); + ulen -= len; + update->length = len; + update->address = __sev_page_pa(inpages[i]); + clflush_cache_range(page_address(inpages[i]), PAGE_SIZE); + + ret = psp_guest_launch_update(update, 5, psp_ret); + if (ret) { + printk(KERN_ERR "SEV: LAUNCH_UPDATE addr %#llx len %d " + "ret=%d (%#010x)\n", update->address, + update->length, ret, *psp_ret); + goto err_3; + } + } + +err_3: + /* mark pages dirty */ + for (i = 0; i < nr_pages; i++) { + set_page_dirty_lock(inpages[i]); + mark_page_accessed(inpages[i]); + } + release_pages(inpages, nr_pages, 0); +err_2: + kfree(inpages); +err_1: + kfree(update); + return ret; +} + static int amd_sev_issue_cmd(struct kvm *kvm, struct kvm_sev_issue_cmd __user *user_data) { @@ -5391,6 +5512,11 @@ static int amd_sev_issue_cmd(struct kvm *kvm, &arg.ret_code); break; } + case KVM_SEV_LAUNCH_UPDATE: { + r = sev_launch_update(kvm, (void *)arg.opaque, + &arg.ret_code); + break; + } default: break; } -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
