From: Joerg Roedel <joro@8bytes.org>
To: x86@kernel.org
Cc: hpa@zytor.com, Andy Lutomirski <luto@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Hellstrom <thellstrom@vmware.com>,
Jiri Slaby <jslaby@suse.cz>,
Dan Williams <dan.j.williams@intel.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
Juergen Gross <jgross@suse.com>,
Kees Cook <keescook@chromium.org>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
virtualization@lists.linux-foundation.org,
Joerg Roedel <joro@8bytes.org>, Joerg Roedel <jroedel@suse.de>
Subject: [PATCH 34/62] x86/sev-es: Setup GHCB based boot #VC handler
Date: Tue, 11 Feb 2020 14:52:28 +0100 [thread overview]
Message-ID: <20200211135256.24617-35-joro@8bytes.org> (raw)
In-Reply-To: <20200211135256.24617-1-joro@8bytes.org>
From: Joerg Roedel <jroedel@suse.de>
Add the infrastructure to handle #VC exceptions when the kernel runs
on virtual addresses and has a GHCB mapped. This handler will be used
until the runtime #VC handler takes over.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
arch/x86/include/asm/segment.h | 2 +-
arch/x86/include/asm/sev-es.h | 1 +
arch/x86/kernel/head64.c | 5 ++
arch/x86/kernel/sev-es-shared.c | 15 ++---
arch/x86/kernel/sev-es.c | 116 ++++++++++++++++++++++++++++++++
arch/x86/mm/extable.c | 1 +
6 files changed, 131 insertions(+), 9 deletions(-)
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index 6669164abadc..5b648066504c 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -230,7 +230,7 @@
#define NUM_EXCEPTION_VECTORS 32
/* Bitmask of exception vectors which push an error code on the stack: */
-#define EXCEPTION_ERRCODE_MASK 0x00027d00
+#define EXCEPTION_ERRCODE_MASK 0x20027d00
#define GDT_SIZE (GDT_ENTRIES*8)
#define GDT_ENTRY_TLS_ENTRIES 3
diff --git a/arch/x86/include/asm/sev-es.h b/arch/x86/include/asm/sev-es.h
index caa29f75ce41..a2d0c77dabc3 100644
--- a/arch/x86/include/asm/sev-es.h
+++ b/arch/x86/include/asm/sev-es.h
@@ -76,5 +76,6 @@ static inline u64 copy_lower_bits(u64 out, u64 in, unsigned int bits)
}
extern void early_vc_handler(void);
+extern int boot_vc_exception(struct pt_regs *regs);
#endif
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index eab04ac260d4..14e0699b2692 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -390,6 +390,11 @@ void __init early_exception(struct pt_regs *regs, int trapnr)
cr2 = native_read_cr2();
r = early_make_pgtable(cr2);
break;
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+ case X86_TRAP_VC:
+ r = boot_vc_exception(regs);
+ break;
+#endif
default:
r = 1;
}
diff --git a/arch/x86/kernel/sev-es-shared.c b/arch/x86/kernel/sev-es-shared.c
index ad2a6c964217..57c29c91fe87 100644
--- a/arch/x86/kernel/sev-es-shared.c
+++ b/arch/x86/kernel/sev-es-shared.c
@@ -9,7 +9,7 @@
* and is included directly into both code-bases.
*/
-static void __maybe_unused terminate(unsigned int reason)
+static void terminate(unsigned int reason)
{
/* Request Guest Termination from Hypvervisor */
write_ghcb_msr(GHCB_SEV_TERMINATE);
@@ -19,7 +19,7 @@ static void __maybe_unused terminate(unsigned int reason)
asm volatile("hlt\n" : : : "memory");
}
-static bool __maybe_unused sev_es_negotiate_protocol(void)
+static bool sev_es_negotiate_protocol(void)
{
u64 val;
@@ -38,7 +38,7 @@ static bool __maybe_unused sev_es_negotiate_protocol(void)
return true;
}
-static void __maybe_unused ghcb_invalidate(struct ghcb *ghcb)
+static void ghcb_invalidate(struct ghcb *ghcb)
{
memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap));
}
@@ -80,10 +80,9 @@ static bool decoding_needed(unsigned long exit_code)
exit_code <= SVM_EXIT_LAST_EXCP);
}
-static enum es_result __maybe_unused
-init_em_ctxt(struct es_em_ctxt *ctxt,
- struct pt_regs *regs,
- unsigned long exit_code)
+static enum es_result init_em_ctxt(struct es_em_ctxt *ctxt,
+ struct pt_regs *regs,
+ unsigned long exit_code)
{
enum es_result ret = ES_OK;
@@ -96,7 +95,7 @@ init_em_ctxt(struct es_em_ctxt *ctxt,
return ret;
}
-static void __maybe_unused finish_insn(struct es_em_ctxt *ctxt)
+static void finish_insn(struct es_em_ctxt *ctxt)
{
ctxt->regs->ip += ctxt->insn.length;
}
diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c
index 33ab7fe8b6a0..0e0b28477627 100644
--- a/arch/x86/kernel/sev-es.c
+++ b/arch/x86/kernel/sev-es.c
@@ -7,15 +7,30 @@
* Author: Joerg Roedel <jroedel@suse.de>
*/
+#include <linux/sched/debug.h> /* For show_regs() */
#include <linux/kernel.h>
+#include <linux/printk.h>
#include <linux/mm.h>
#include <asm/trap_defs.h>
#include <asm/sev-es.h>
#include <asm/fpu/internal.h>
#include <asm/processor.h>
+#include <asm/trap_defs.h>
#include <asm/svm.h>
+/* For early boot hypervisor communication in SEV-ES enabled guests */
+struct ghcb boot_ghcb_page __bss_decrypted __aligned(PAGE_SIZE);
+
+/*
+ * Needs to be in the .data section because we need it NULL before bss is
+ * cleared
+ */
+struct ghcb __initdata *boot_ghcb;
+
+/* Needed in early_forward_exception */
+extern void early_exception(struct pt_regs *regs, int trapnr);
+
static inline u64 read_ghcb_msr(void)
{
return native_read_msr(MSR_AMD64_SEV_ES_GHCB);
@@ -96,3 +111,104 @@ static phys_addr_t es_slow_virt_to_phys(struct ghcb *ghcb, long vaddr)
/* Include code shared with pre-decompression boot stage */
#include "sev-es-shared.c"
+
+/*
+ * This function runs on the first #VC exception after the kernel
+ * switched to virtual addresses.
+ */
+static bool __init setup_ghcb(void)
+{
+ /* First make sure the hypervisor talks a supported protocol. */
+ if (!sev_es_negotiate_protocol())
+ return false;
+ /*
+ * Clear the boot_ghcb. The first exception comes in before the bss
+ * section is cleared.
+ */
+ memset(&boot_ghcb_page, 0, PAGE_SIZE);
+
+ /* Alright - Make the boot-ghcb public */
+ boot_ghcb = &boot_ghcb_page;
+
+ return true;
+}
+
+static void __init early_forward_exception(struct es_em_ctxt *ctxt)
+{
+ int trapnr = ctxt->fi.vector;
+
+ if (trapnr == X86_TRAP_PF)
+ native_write_cr2(ctxt->fi.cr2);
+
+ ctxt->regs->orig_ax = ctxt->fi.error_code;
+ early_exception(ctxt->regs, trapnr);
+}
+
+static enum es_result handle_vc_exception(struct es_em_ctxt *ctxt,
+ struct ghcb *ghcb,
+ unsigned long exit_code)
+{
+ enum es_result result;
+
+ switch (exit_code) {
+ default:
+ /*
+ * Unexpected #VC exception
+ */
+ result = ES_UNSUPPORTED;
+ }
+
+ return result;
+}
+
+int __init boot_vc_exception(struct pt_regs *regs)
+{
+ unsigned long exit_code = regs->orig_ax;
+ struct es_em_ctxt ctxt;
+ enum es_result result;
+
+ /* Do initial setup or terminate the guest */
+ if (unlikely(boot_ghcb == NULL && !setup_ghcb()))
+ terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
+
+ ghcb_invalidate(boot_ghcb);
+ result = init_em_ctxt(&ctxt, regs, exit_code);
+
+ if (result == ES_OK)
+ result = handle_vc_exception(&ctxt, boot_ghcb, exit_code);
+
+ /* Done - now check the result */
+ switch (result) {
+ case ES_OK:
+ finish_insn(&ctxt);
+ break;
+ case ES_UNSUPPORTED:
+ early_printk("PANIC: Unsupported exit-code 0x%02lx in early #VC exception (IP: 0x%lx)\n",
+ exit_code, regs->ip);
+ goto fail;
+ case ES_VMM_ERROR:
+ early_printk("PANIC: Failure in communication with VMM (exit-code 0x%02lx IP: 0x%lx)\n",
+ exit_code, regs->ip);
+ goto fail;
+ case ES_DECODE_FAILED:
+ early_printk("PANIC: Failed to decode instruction (exit-code 0x%02lx IP: 0x%lx)\n",
+ exit_code, regs->ip);
+ goto fail;
+ case ES_EXCEPTION:
+ early_forward_exception(&ctxt);
+ break;
+ case ES_RETRY:
+ /* Nothing to do */
+ break;
+ default:
+ BUG();
+ }
+
+ return 0;
+
+fail:
+ show_regs(regs);
+
+ while (true)
+ halt();
+}
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 30bb0bd3b1b8..cd440a9cf422 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -5,6 +5,7 @@
#include <xen/xen.h>
#include <asm/fpu/internal.h>
+#include <asm/sev-es.h>
#include <asm/traps.h>
#include <asm/kdebug.h>
--
2.17.1
next prev parent reply other threads:[~2020-02-11 13:56 UTC|newest]
Thread overview: 109+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-11 13:51 [RFC PATCH 00/62] Linux as SEV-ES Guest Support Joerg Roedel
2020-02-11 13:51 ` [PATCH 01/62] KVM: SVM: Add GHCB definitions Joerg Roedel
2020-02-11 13:51 ` [PATCH 02/62] KVM: SVM: Add GHCB Accessor functions Joerg Roedel
2020-02-11 13:51 ` [PATCH 03/62] x86/cpufeatures: Add SEV-ES CPU feature Joerg Roedel
2020-02-13 6:51 ` Borislav Petkov
2020-02-11 13:51 ` [PATCH 04/62] x86/traps: Move some definitions to <asm/trap_defs.h> Joerg Roedel
2020-02-11 13:51 ` [PATCH 05/62] x86/insn-decoder: Make inat-tables.c suitable for pre-decompression code Joerg Roedel
2020-02-11 13:52 ` [PATCH 06/62] x86/boot/compressed: Fix debug_puthex() parameter type Joerg Roedel
2020-02-11 13:52 ` [PATCH 07/62] x86/boot/compressed/64: Disable red-zone usage Joerg Roedel
2020-02-11 22:13 ` Andy Lutomirski
2020-02-11 13:52 ` [PATCH 08/62] x86/boot/compressed/64: Add IDT Infrastructure Joerg Roedel
2020-02-11 22:18 ` Andy Lutomirski
2020-02-12 11:19 ` Joerg Roedel
2020-02-14 19:40 ` Andi Kleen
2020-02-15 12:32 ` Joerg Roedel
2020-02-11 13:52 ` [PATCH 09/62] x86/boot/compressed/64: Rename kaslr_64.c to ident_map_64.c Joerg Roedel
2020-02-11 13:52 ` [PATCH 10/62] x86/boot/compressed/64: Add page-fault handler Joerg Roedel
2020-02-11 13:52 ` [PATCH 11/62] x86/boot/compressed/64: Always switch to own page-table Joerg Roedel
2020-02-11 13:52 ` [PATCH 12/62] x86/boot/compressed/64: Don't pre-map memory in KASLR code Joerg Roedel
2020-02-11 13:52 ` [PATCH 13/62] x86/boot/compressed/64: Change add_identity_map() to take start and end Joerg Roedel
2020-02-11 13:52 ` [PATCH 14/62] x86/boot/compressed/64: Add stage1 #VC handler Joerg Roedel
2020-02-11 22:23 ` Andy Lutomirski
2020-02-12 11:38 ` Joerg Roedel
2020-02-12 16:22 ` Andy Lutomirski
2020-02-11 13:52 ` [PATCH 15/62] x86/boot/compressed/64: Call set_sev_encryption_mask earlier Joerg Roedel
2020-02-11 13:52 ` [PATCH 16/62] x86/boot/compressed/64: Check return value of kernel_ident_mapping_init() Joerg Roedel
2020-02-11 13:52 ` [PATCH 17/62] x86/boot/compressed/64: Add function to map a page unencrypted Joerg Roedel
2020-02-11 13:52 ` [PATCH 18/62] x86/boot/compressed/64: Setup GHCB Based VC Exception handler Joerg Roedel
2020-02-11 22:25 ` Andy Lutomirski
2020-02-12 11:44 ` Joerg Roedel
2020-02-11 13:52 ` [PATCH 19/62] x86/sev-es: Add support for handling IOIO exceptions Joerg Roedel
2020-02-11 22:28 ` Andy Lutomirski
2020-02-12 11:49 ` Joerg Roedel
2020-02-11 13:52 ` [PATCH 20/62] x86/fpu: Move xgetbv()/xsetbv() into separate header Joerg Roedel
2020-02-11 13:52 ` [PATCH 21/62] x86/sev-es: Add CPUID handling to #VC handler Joerg Roedel
2020-02-11 13:52 ` [PATCH 22/62] x86/sev-es: Add handler for MMIO events Joerg Roedel
2020-02-11 13:52 ` [PATCH 23/62] x86/idt: Move IDT to data segment Joerg Roedel
2020-02-11 22:41 ` Andy Lutomirski
2020-02-12 11:55 ` Joerg Roedel
2020-02-12 16:23 ` Andy Lutomirski
2020-02-12 16:28 ` Jürgen Groß
2020-02-19 10:42 ` Joerg Roedel
2020-02-19 10:47 ` Jürgen Groß
2020-02-11 13:52 ` [PATCH 24/62] x86/idt: Split idt_data setup out of set_intr_gate() Joerg Roedel
2020-02-11 13:52 ` [PATCH 25/62] x86/head/64: Install boot GDT Joerg Roedel
2020-02-11 22:29 ` Andy Lutomirski
2020-02-12 12:20 ` Joerg Roedel
2020-02-11 13:52 ` [PATCH 26/62] x86/head/64: Reload GDT after switch to virtual addresses Joerg Roedel
2020-02-11 13:52 ` [PATCH 27/62] x86/head/64: Load segment registers earlier Joerg Roedel
2020-02-11 13:52 ` [PATCH 28/62] x86/head/64: Switch to initial stack earlier Joerg Roedel
2020-02-11 13:52 ` [PATCH 29/62] x86/head/64: Load IDT earlier Joerg Roedel
2020-02-11 13:52 ` [PATCH 30/62] x86/head/64: Move early exception dispatch to C code Joerg Roedel
2020-02-11 22:44 ` Andy Lutomirski
2020-02-12 12:39 ` Joerg Roedel
2020-02-11 13:52 ` [PATCH 31/62] x86/sev-es: Add SEV-ES Feature Detection Joerg Roedel
2020-02-11 13:52 ` [PATCH 32/62] x86/sev-es: Compile early handler code into kernel image Joerg Roedel
2020-02-11 13:52 ` [PATCH 33/62] x86/sev-es: Setup early #VC handler Joerg Roedel
2020-02-11 13:52 ` Joerg Roedel [this message]
2020-02-11 13:52 ` [PATCH 35/62] x86/sev-es: Setup per-cpu GHCBs for the runtime handler Joerg Roedel
2020-02-11 22:46 ` Andy Lutomirski
2020-02-12 15:16 ` Joerg Roedel
2020-02-11 13:52 ` [PATCH 36/62] x86/sev-es: Add Runtime #VC Exception Handler Joerg Roedel
2020-02-11 13:52 ` [PATCH 37/62] x86/sev-es: Wire up existing #VC exit-code handlers Joerg Roedel
2020-02-11 13:52 ` [PATCH 38/62] x86/sev-es: Handle instruction fetches from user-space Joerg Roedel
2020-02-12 21:42 ` Andy Lutomirski
2020-03-13 9:12 ` Joerg Roedel
2020-03-17 21:34 ` Andy Lutomirski
2020-02-11 13:52 ` [PATCH 39/62] x86/sev-es: Harden runtime #VC handler for exceptions " Joerg Roedel
2020-02-11 22:47 ` Andy Lutomirski
2020-02-12 13:16 ` Joerg Roedel
2020-02-11 13:52 ` [PATCH 40/62] x86/sev-es: Filter exceptions not supported " Joerg Roedel
2020-02-11 13:52 ` [PATCH 41/62] x86/sev-es: Handle MSR events Joerg Roedel
2020-02-13 15:45 ` Dave Hansen
2020-02-14 7:23 ` Joerg Roedel
2020-02-14 16:59 ` Dave Hansen
2020-02-15 12:45 ` Joerg Roedel
2020-02-11 13:52 ` [PATCH 42/62] x86/sev-es: Handle DR7 read/write events Joerg Roedel
2020-02-11 13:52 ` [PATCH 43/62] x86/sev-es: Handle WBINVD Events Joerg Roedel
2020-02-11 13:52 ` [PATCH 44/62] x86/sev-es: Handle RDTSC Events Joerg Roedel
2020-02-11 13:52 ` [PATCH 45/62] x86/sev-es: Handle RDPMC Events Joerg Roedel
2020-02-11 13:52 ` [PATCH 46/62] x86/sev-es: Handle INVD Events Joerg Roedel
2020-02-12 0:12 ` Andy Lutomirski
2020-02-12 15:36 ` Joerg Roedel
2020-02-11 13:52 ` [PATCH 47/62] x86/sev-es: Handle RDTSCP Events Joerg Roedel
2020-02-11 13:52 ` [PATCH 48/62] x86/sev-es: Handle MONITOR/MONITORX Events Joerg Roedel
2020-02-11 13:52 ` [PATCH 49/62] x86/sev-es: Handle MWAIT/MWAITX Events Joerg Roedel
2020-02-11 13:52 ` [PATCH 50/62] x86/sev-es: Handle VMMCALL Events Joerg Roedel
2020-02-12 0:14 ` Andy Lutomirski
2020-02-12 13:22 ` Joerg Roedel
2020-02-11 13:52 ` [PATCH 51/62] x86/sev-es: Handle #AC Events Joerg Roedel
2020-02-11 13:52 ` [PATCH 52/62] x86/sev-es: Handle #DB Events Joerg Roedel
2020-02-11 13:52 ` [PATCH 53/62] x86/paravirt: Allow hypervisor specific VMMCALL handling under SEV-ES Joerg Roedel
2020-02-11 13:52 ` [PATCH 54/62] x86/kvm: Add KVM " Joerg Roedel
2020-02-11 13:52 ` [PATCH 55/62] x86/vmware: Add VMware specific handling for VMMCALL " Joerg Roedel
2020-02-11 13:52 ` [PATCH 56/62] x86/realmode: Add SEV-ES specific trampoline entry point Joerg Roedel
2020-02-11 13:52 ` [PATCH 57/62] x86/realmode: Setup AP jump table Joerg Roedel
2020-02-11 13:52 ` [PATCH 58/62] x86/head/64: Don't call verify_cpu() on starting APs Joerg Roedel
2020-02-11 13:52 ` [PATCH 59/62] x86/head/64: Rename start_cpu0 Joerg Roedel
2020-02-11 13:52 ` [PATCH 60/62] x86/sev-es: Support CPU offline/online Joerg Roedel
2020-02-11 13:52 ` [PATCH 61/62] x86/cpufeature: Add SEV_ES_GUEST CPU Feature Joerg Roedel
2020-02-11 13:52 ` [PATCH 62/62] x86/sev-es: Add NMI state tracking Joerg Roedel
2020-02-11 22:50 ` Andy Lutomirski
2020-02-12 13:56 ` Joerg Roedel
2020-02-11 14:50 ` [RFC PATCH 00/62] Linux as SEV-ES Guest Support Peter Zijlstra
2020-02-11 15:43 ` Joerg Roedel
2020-02-11 22:12 ` Andy Lutomirski
2020-02-12 13:54 ` Joerg Roedel
2020-02-12 3:48 ` Andy Lutomirski
2020-02-12 13:59 ` Joerg Roedel
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