From: Brijesh Singh <brijesh.singh@amd.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org
Cc: "Thomas Gleixner" <tglx@linutronix.de>,
"Borislav Petkov" <bp@suse.de>, "Joerg Roedel" <joro@8bytes.org>,
"Michael S . Tsirkin" <mst@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"\\\"Radim Krčmář\\\"" <rkrcmar@redhat.com>,
"Tom Lendacky" <thomas.lendacky@amd.com>,
"Brijesh Singh" <brijesh.singh@amd.com>
Subject: [RFC Part2 PATCH v3 20/26] KVM: SVM: Add support for SEV DEBUG_DECRYPT command
Date: Mon, 24 Jul 2017 15:02:57 -0500 [thread overview]
Message-ID: <20170724200303.12197-21-brijesh.singh@amd.com> (raw)
In-Reply-To: <20170724200303.12197-1-brijesh.singh@amd.com>
The command is used for decrypting a guest memory region for debug
purposes.
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
arch/x86/kvm/svm.c | 160 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 160 insertions(+)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 21f85e1..933384a 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6058,6 +6058,162 @@ static int sev_guest_status(struct kvm *kvm, struct kvm_sev_cmd *argp)
return ret;
}
+static int __sev_dbg_enc_dec(struct kvm *kvm, unsigned long src,
+ unsigned long dst, int size, int *error, bool enc)
+{
+ struct sev_data_dbg *data;
+ int ret;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->handle = sev_get_handle(kvm);
+ data->dst_addr = dst;
+ data->src_addr = src;
+ data->length = size;
+
+ ret = sev_issue_cmd(kvm,
+ enc ? SEV_CMD_DBG_ENCRYPT : SEV_CMD_DBG_DECRYPT,
+ data, error);
+ kfree(data);
+ return ret;
+}
+
+/*
+ * Decrypt source memory into userspace or kernel buffer. If destination buffer
+ * or len is not aligned to 16-byte boundary then it uses intermediate buffer.
+ */
+static int __sev_dbg_dec(struct kvm *kvm, unsigned long paddr,
+ unsigned long __user dst_uaddr,
+ unsigned long dst_kaddr, unsigned long dst_paddr,
+ int size, int *error)
+{
+ int ret, offset, len = size;
+ struct page *tpage = NULL;
+
+ /*
+ * Debug command works with 16-byte aligned inputs, check if all inputs
+ * (src, dst and len) are 16-byte aligned. If one of the input is not
+ * aligned then we decrypt more than requested into a temporary buffer
+ * and copy the porition of data into destination buffer.
+ */
+ if (!IS_ALIGNED(paddr, 16) || !IS_ALIGNED(dst_paddr, 16) ||
+ !IS_ALIGNED(size, 16)) {
+ tpage = (void *)alloc_page(GFP_KERNEL);
+ if (!tpage)
+ return -ENOMEM;
+
+ dst_paddr = __sme_page_pa(tpage);
+
+ /*
+ * if source buffer is not aligned then offset will be used
+ * when copying the data from the temporary buffer into
+ * destination buffer.
+ */
+ offset = paddr & 15;
+
+ /* its safe to read more than requested size. */
+ len = round_up(size + offset, 16);
+
+ paddr = round_down(paddr, 16);
+ }
+
+ ret = __sev_dbg_enc_dec(kvm, paddr, dst_paddr, len, error, false);
+ /*
+ * If temporary buffer is used then copy the data from temporary buffer
+ * into destination buffer.
+ */
+ if (tpage) {
+
+ /*
+ * If destination buffer is a userspace buffer then use
+ * copy_to_user otherwise memcpy.
+ */
+ if (dst_uaddr) {
+ if (copy_to_user((uint8_t *)dst_uaddr,
+ page_address(tpage) + offset, size))
+ ret = -EFAULT;
+ } else {
+ memcpy((void *)dst_kaddr,
+ page_address(tpage) + offset, size);
+ }
+
+ __free_page(tpage);
+ }
+
+ return ret;
+}
+
+static int sev_dbg_decrypt(struct kvm *kvm, struct kvm_sev_cmd *argp)
+{
+ unsigned long vaddr, vaddr_end, next_vaddr;
+ unsigned long dst_vaddr, dst_vaddr_end;
+ struct page **srcpage, **dstpage;
+ struct kvm_sev_dbg debug;
+ unsigned long n;
+ int ret, size;
+
+ if (!sev_guest(kvm))
+ return -ENOTTY;
+
+ if (copy_from_user(&debug, (void *)argp->data,
+ sizeof(struct kvm_sev_dbg)))
+ return -EFAULT;
+
+ vaddr = debug.src_addr;
+ size = debug.length;
+ vaddr_end = vaddr + size;
+ dst_vaddr = debug.dst_addr;
+ dst_vaddr_end = dst_vaddr + size;
+
+ for (; vaddr < vaddr_end; vaddr = next_vaddr) {
+ int len, s_off, d_off;
+
+ /* lock userspace source and destination page */
+ srcpage = sev_pin_memory(vaddr & PAGE_MASK, PAGE_SIZE, &n, 0);
+ if (!srcpage)
+ return -EFAULT;
+
+ dstpage = sev_pin_memory(dst_vaddr & PAGE_MASK, PAGE_SIZE,
+ &n, 1);
+ if (!dstpage) {
+ sev_unpin_memory(srcpage, n);
+ return -EFAULT;
+ }
+
+ /* flush the caches to ensure that DRAM has recent contents */
+ sev_clflush_pages(srcpage, 1);
+ sev_clflush_pages(dstpage, 1);
+
+ /*
+ * since user buffer may not be page aligned, calculate the
+ * offset within the page.
+ */
+ s_off = vaddr & ~PAGE_MASK;
+ d_off = dst_vaddr & ~PAGE_MASK;
+ len = min_t(size_t, (PAGE_SIZE - s_off), size);
+
+ ret = __sev_dbg_dec(kvm,
+ __sme_page_pa(srcpage[0]) + s_off,
+ dst_vaddr, 0,
+ __sme_page_pa(dstpage[0]) + d_off,
+ len, &argp->error);
+
+ sev_unpin_memory(srcpage, 1);
+ sev_unpin_memory(dstpage, 1);
+
+ if (ret)
+ goto err;
+
+ next_vaddr = vaddr + len;
+ dst_vaddr = dst_vaddr + len;
+ size -= len;
+ }
+err:
+ return ret;
+}
+
static int svm_memory_encryption_op(struct kvm *kvm, void __user *argp)
{
struct kvm_sev_cmd sev_cmd;
@@ -6093,6 +6249,10 @@ static int svm_memory_encryption_op(struct kvm *kvm, void __user *argp)
r = sev_guest_status(kvm, &sev_cmd);
break;
}
+ case KVM_SEV_DBG_DECRYPT: {
+ r = sev_dbg_decrypt(kvm, &sev_cmd);
+ break;
+ }
default:
break;
}
--
2.9.4
next prev parent reply other threads:[~2017-07-24 20:11 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-24 20:02 [RFC Part2 PATCH v3 00/26] x86: Secure Encrypted Virtualization (AMD) Brijesh Singh
2017-07-24 20:02 ` [RFC Part2 PATCH v3 01/26] Documentation/virtual/kvm: Add AMD Secure Encrypted Virtualization (SEV) Brijesh Singh
2017-09-05 17:21 ` Borislav Petkov
2017-09-05 21:39 ` Brijesh Singh
2017-09-05 22:06 ` Borislav Petkov
2017-09-06 16:41 ` Borislav Petkov
2017-09-06 20:54 ` Brijesh Singh
2017-07-24 20:02 ` [RFC Part2 PATCH v3 02/26] crypto: ccp: Add Platform Security Processor (PSP) device support Brijesh Singh
2017-07-25 8:29 ` Kamil Konieczny
2017-07-25 15:00 ` Brijesh Singh
2017-09-06 17:00 ` Borislav Petkov
2017-09-06 20:38 ` Brijesh Singh
2017-09-06 20:46 ` Borislav Petkov
2017-09-06 21:26 ` Gary R Hook
2017-09-07 10:34 ` Borislav Petkov
2017-09-07 14:27 ` Borislav Petkov
2017-09-07 22:19 ` Brijesh Singh
2017-09-07 23:15 ` Gary R Hook
2017-09-08 8:22 ` Borislav Petkov
2017-09-08 8:40 ` Borislav Petkov
2017-09-08 13:54 ` Brijesh Singh
2017-09-08 16:06 ` Brijesh Singh
2017-07-24 20:02 ` [RFC Part2 PATCH v3 03/26] crypto: ccp: Add Secure Encrypted Virtualization (SEV) " Brijesh Singh
2017-09-12 14:02 ` Borislav Petkov
2017-09-12 15:32 ` Brijesh Singh
2017-09-12 16:29 ` Borislav Petkov
2017-09-13 14:17 ` Borislav Petkov
2017-09-13 15:18 ` Brijesh Singh
2017-07-24 20:02 ` [RFC Part2 PATCH v3 04/26] KVM: SVM: Prepare to reserve asid for SEV guest Brijesh Singh
2017-09-12 19:54 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 05/26] KVM: SVM: Reserve ASID range " Brijesh Singh
2017-09-12 20:04 ` Borislav Petkov
2017-09-12 20:24 ` Brijesh Singh
2017-09-12 20:28 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 06/26] KVM: SVM: Prepare for new bit definition in nested_ctl Brijesh Singh
2017-09-12 20:06 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 07/26] KVM: SVM: Add SEV feature definitions to KVM Brijesh Singh
2017-09-12 20:08 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 08/26] KVM: X86: Extend CPUID range to include new leaf Brijesh Singh
2017-09-12 20:12 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 09/26] KVM: Introduce KVM_MEMORY_ENCRYPT_OP ioctl Brijesh Singh
2017-09-12 20:19 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 10/26] KVM: Introduce KVM_MEMORY_ENCRYPT_REGISTER/UNREGISTER_RAM ioctl Brijesh Singh
2017-09-12 20:29 ` Borislav Petkov
2017-09-12 20:50 ` Brijesh Singh
2017-09-12 21:08 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 11/26] KVM: X86: Extend struct kvm_arch to include SEV information Brijesh Singh
2017-09-13 13:37 ` Borislav Petkov
2017-09-13 15:14 ` Brijesh Singh
2017-09-13 15:21 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 12/26] KVM: Define SEV key management command id Brijesh Singh
2017-09-13 13:45 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 13/26] KVM: SVM: Add KVM_SEV_INIT command Brijesh Singh
2017-09-13 15:06 ` Borislav Petkov
2017-09-13 16:23 ` Brijesh Singh
2017-09-13 16:37 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 14/26] KVM: SVM: VMRUN should use assosiated ASID when SEV is enabled Brijesh Singh
2017-09-13 15:37 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 15/26] KVM: SVM: Add support for SEV LAUNCH_START command Brijesh Singh
2017-09-13 17:25 ` Borislav Petkov
2017-09-13 18:23 ` Brijesh Singh
2017-09-13 18:37 ` Borislav Petkov
2017-09-13 18:58 ` Brijesh Singh
2017-09-13 21:02 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 16/26] KVM: SVM: Add support for SEV LAUNCH_UPDATE_DATA command Brijesh Singh
2017-09-13 17:55 ` Borislav Petkov
2017-09-13 19:45 ` Brijesh Singh
2017-09-13 21:07 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 17/26] KVM: SVM: Add support for SEV LAUNCH_MEASURE command Brijesh Singh
2017-09-14 10:20 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 18/26] KVM: SVM: Add support for SEV LAUNCH_FINISH command Brijesh Singh
2017-09-14 10:24 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 19/26] KVM: svm: Add support for SEV GUEST_STATUS command Brijesh Singh
2017-09-14 10:35 ` Borislav Petkov
2017-09-14 11:25 ` Brijesh Singh
2017-07-24 20:02 ` Brijesh Singh [this message]
2017-09-14 11:08 ` [RFC Part2 PATCH v3 20/26] KVM: SVM: Add support for SEV DEBUG_DECRYPT command Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 21/26] KVM: SVM: Add support for SEV DEBUG_ENCRYPT command Brijesh Singh
2017-09-14 13:32 ` Borislav Petkov
2017-07-24 20:02 ` [RFC Part2 PATCH v3 22/26] KVM: SVM: Pin guest memory when SEV is active Brijesh Singh
2017-09-14 14:00 ` Borislav Petkov
2017-07-24 20:03 ` [RFC Part2 PATCH v3 23/26] KVM: X86: Add memory encryption enabled ops Brijesh Singh
2017-09-14 14:09 ` Borislav Petkov
2017-07-24 20:03 ` [RFC Part2 PATCH v3 24/26] KVM: SVM: Clear C-bit from the page fault address Brijesh Singh
2017-09-14 14:35 ` Borislav Petkov
2017-07-24 20:03 ` [RFC Part2 PATCH v3 25/26] KVM: SVM: Do not install #UD intercept when SEV is enabled Brijesh Singh
2017-09-14 14:56 ` Borislav Petkov
2017-07-24 20:03 ` [RFC Part2 PATCH v3 26/26] KVM: X86: Restart the guest when insn_len is zero and " Brijesh Singh
2017-09-14 15:40 ` Borislav Petkov
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