Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 155 insertions, 0 deletions

diff --git a/arch/x86/coco/core.c b/arch/x86/coco/core.c
new file mode 100644
index 0000000000..eeec998657
--- /dev/null
+++ b/arch/x86/coco/core.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Confidential Computing Platform Capability checks
+ *
+ * Copyright (C) 2021 Advanced Micro Devices, Inc.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ */
+
+#include <linux/export.h>
+#include <linux/cc_platform.h>
+
+#include <asm/coco.h>
+#include <asm/processor.h>
+
+enum cc_vendor cc_vendor __ro_after_init = CC_VENDOR_NONE;
+static u64 cc_mask __ro_after_init;
+
+static bool noinstr intel_cc_platform_has(enum cc_attr attr)
+{
+	switch (attr) {
+	case CC_ATTR_GUEST_UNROLL_STRING_IO:
+	case CC_ATTR_HOTPLUG_DISABLED:
+	case CC_ATTR_GUEST_MEM_ENCRYPT:
+	case CC_ATTR_MEM_ENCRYPT:
+		return true;
+	default:
+		return false;
+	}
+}
+
+/*
+ * Handle the SEV-SNP vTOM case where sme_me_mask is zero, and
+ * the other levels of SME/SEV functionality, including C-bit
+ * based SEV-SNP, are not enabled.
+ */
+static __maybe_unused __always_inline bool amd_cc_platform_vtom(enum cc_attr attr)
+{
+	switch (attr) {
+	case CC_ATTR_GUEST_MEM_ENCRYPT:
+	case CC_ATTR_MEM_ENCRYPT:
+		return true;
+	default:
+		return false;
+	}
+}
+
+/*
+ * SME and SEV are very similar but they are not the same, so there are
+ * times that the kernel will need to distinguish between SME and SEV. The
+ * cc_platform_has() function is used for this.  When a distinction isn't
+ * needed, the CC_ATTR_MEM_ENCRYPT attribute can be used.
+ *
+ * The trampoline code is a good example for this requirement.  Before
+ * paging is activated, SME will access all memory as decrypted, but SEV
+ * will access all memory as encrypted.  So, when APs are being brought
+ * up under SME the trampoline area cannot be encrypted, whereas under SEV
+ * the trampoline area must be encrypted.
+ */
+
+static bool noinstr amd_cc_platform_has(enum cc_attr attr)
+{
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+
+	if (sev_status & MSR_AMD64_SNP_VTOM)
+		return amd_cc_platform_vtom(attr);
+
+	switch (attr) {
+	case CC_ATTR_MEM_ENCRYPT:
+		return sme_me_mask;
+
+	case CC_ATTR_HOST_MEM_ENCRYPT:
+		return sme_me_mask && !(sev_status & MSR_AMD64_SEV_ENABLED);
+
+	case CC_ATTR_GUEST_MEM_ENCRYPT:
+		return sev_status & MSR_AMD64_SEV_ENABLED;
+
+	case CC_ATTR_GUEST_STATE_ENCRYPT:
+		return sev_status & MSR_AMD64_SEV_ES_ENABLED;
+
+	/*
+	 * With SEV, the rep string I/O instructions need to be unrolled
+	 * but SEV-ES supports them through the #VC handler.
+	 */
+	case CC_ATTR_GUEST_UNROLL_STRING_IO:
+		return (sev_status & MSR_AMD64_SEV_ENABLED) &&
+			!(sev_status & MSR_AMD64_SEV_ES_ENABLED);
+
+	case CC_ATTR_GUEST_SEV_SNP:
+		return sev_status & MSR_AMD64_SEV_SNP_ENABLED;
+
+	default:
+		return false;
+	}
+#else
+	return false;
+#endif
+}
+
+bool noinstr cc_platform_has(enum cc_attr attr)
+{
+	switch (cc_vendor) {
+	case CC_VENDOR_AMD:
+		return amd_cc_platform_has(attr);
+	case CC_VENDOR_INTEL:
+		return intel_cc_platform_has(attr);
+	default:
+		return false;
+	}
+}
+EXPORT_SYMBOL_GPL(cc_platform_has);
+
+u64 cc_mkenc(u64 val)
+{
+	/*
+	 * Both AMD and Intel use a bit in the page table to indicate
+	 * encryption status of the page.
+	 *
+	 * - for AMD, bit *set* means the page is encrypted
+	 * - for AMD with vTOM and for Intel, *clear* means encrypted
+	 */
+	switch (cc_vendor) {
+	case CC_VENDOR_AMD:
+		if (sev_status & MSR_AMD64_SNP_VTOM)
+			return val & ~cc_mask;
+		else
+			return val | cc_mask;
+	case CC_VENDOR_INTEL:
+		return val & ~cc_mask;
+	default:
+		return val;
+	}
+}
+
+u64 cc_mkdec(u64 val)
+{
+	/* See comment in cc_mkenc() */
+	switch (cc_vendor) {
+	case CC_VENDOR_AMD:
+		if (sev_status & MSR_AMD64_SNP_VTOM)
+			return val | cc_mask;
+		else
+			return val & ~cc_mask;
+	case CC_VENDOR_INTEL:
+		return val | cc_mask;
+	default:
+		return val;
+	}
+}
+EXPORT_SYMBOL_GPL(cc_mkdec);
+
+__init void cc_set_mask(u64 mask)
+{
+	cc_mask = mask;
+}