iommu/amd: Allow the AMD IOMMU to work with memory encryption

The IOMMU is programmed with physical addresses for the various tables
and buffers that are used to communicate between the device and the
driver. When the driver allocates this memory it is encrypted. In order
for the IOMMU to access the memory as encrypted the encryption mask needs
to be included in these physical addresses during configuration.

The PTE entries created by the IOMMU should also include the encryption
mask so that when the device behind the IOMMU performs a DMA, the DMA
will be performed to encrypted memory.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
Cc: <iommu@lists.linux-foundation.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Toshimitsu Kani <toshi.kani@hpe.com>
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/3053631ea25ba8b1601c351cb7c541c496f6d9bc.1500319216.git.thomas.lendacky@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 28 insertions, 6 deletions

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 5cc597b383c7..42ff9a86c102 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -30,6 +30,7 @@
 #include <linux/iommu.h>
 #include <linux/kmemleak.h>
 #include <linux/crash_dump.h>
+#include <linux/mem_encrypt.h>
 #include <asm/pci-direct.h>
 #include <asm/iommu.h>
 #include <asm/gart.h>
@@ -348,7 +349,7 @@ static void iommu_set_device_table(struct amd_iommu *iommu)
 
 	BUG_ON(iommu->mmio_base == NULL);
 
-	entry = virt_to_phys(amd_iommu_dev_table);
+	entry = iommu_virt_to_phys(amd_iommu_dev_table);
 	entry |= (dev_table_size >> 12) - 1;
 	memcpy_toio(iommu->mmio_base + MMIO_DEV_TABLE_OFFSET,
 			&entry, sizeof(entry));
@@ -606,7 +607,7 @@ static void iommu_enable_command_buffer(struct amd_iommu *iommu)
 
 	BUG_ON(iommu->cmd_buf == NULL);
 
-	entry = (u64)virt_to_phys(iommu->cmd_buf);
+	entry = iommu_virt_to_phys(iommu->cmd_buf);
 	entry |= MMIO_CMD_SIZE_512;
 
 	memcpy_toio(iommu->mmio_base + MMIO_CMD_BUF_OFFSET,
@@ -635,7 +636,7 @@ static void iommu_enable_event_buffer(struct amd_iommu *iommu)
 
 	BUG_ON(iommu->evt_buf == NULL);
 
-	entry = (u64)virt_to_phys(iommu->evt_buf) | EVT_LEN_MASK;
+	entry = iommu_virt_to_phys(iommu->evt_buf) | EVT_LEN_MASK;
 
 	memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET,
 		    &entry, sizeof(entry));
@@ -668,7 +669,7 @@ static void iommu_enable_ppr_log(struct amd_iommu *iommu)
 	if (iommu->ppr_log == NULL)
 		return;
 
-	entry = (u64)virt_to_phys(iommu->ppr_log) | PPR_LOG_SIZE_512;
+	entry = iommu_virt_to_phys(iommu->ppr_log) | PPR_LOG_SIZE_512;
 
 	memcpy_toio(iommu->mmio_base + MMIO_PPR_LOG_OFFSET,
 		    &entry, sizeof(entry));
@@ -748,10 +749,10 @@ static int iommu_init_ga_log(struct amd_iommu *iommu)
 	if (!iommu->ga_log_tail)
 		goto err_out;
 
-	entry = (u64)virt_to_phys(iommu->ga_log) | GA_LOG_SIZE_512;
+	entry = iommu_virt_to_phys(iommu->ga_log) | GA_LOG_SIZE_512;
 	memcpy_toio(iommu->mmio_base + MMIO_GA_LOG_BASE_OFFSET,
 		    &entry, sizeof(entry));
-	entry = ((u64)virt_to_phys(iommu->ga_log) & 0xFFFFFFFFFFFFFULL) & ~7ULL;
+	entry = (iommu_virt_to_phys(iommu->ga_log) & 0xFFFFFFFFFFFFFULL) & ~7ULL;
 	memcpy_toio(iommu->mmio_base + MMIO_GA_LOG_TAIL_OFFSET,
 		    &entry, sizeof(entry));
 	writel(0x00, iommu->mmio_base + MMIO_GA_HEAD_OFFSET);
@@ -2564,6 +2565,24 @@ static int __init amd_iommu_init(void)
 	return ret;
 }
 
+static bool amd_iommu_sme_check(void)
+{
+	if (!sme_active() || (boot_cpu_data.x86 != 0x17))
+		return true;
+
+	/* For Fam17h, a specific level of support is required */
+	if (boot_cpu_data.microcode >= 0x08001205)
+		return true;
+
+	if ((boot_cpu_data.microcode >= 0x08001126) &&
+	    (boot_cpu_data.microcode <= 0x080011ff))
+		return true;
+
+	pr_notice("AMD-Vi: IOMMU not currently supported when SME is active\n");
+
+	return false;
+}
+
 /****************************************************************************
  *
  * Early detect code. This code runs at IOMMU detection time in the DMA
@@ -2578,6 +2597,9 @@ int __init amd_iommu_detect(void)
 	if (no_iommu || (iommu_detected && !gart_iommu_aperture))
 		return -ENODEV;
 
+	if (!amd_iommu_sme_check())
+		return -ENODEV;
+
 	ret = iommu_go_to_state(IOMMU_IVRS_DETECTED);
 	if (ret)
 		return ret;