From: Joerg Roedel <joro@8bytes.org>
To: x86@kernel.org
Cc: Joerg Roedel <joro@8bytes.org>, Joerg Roedel <jroedel@suse.de>,
hpa@zytor.com, Andy Lutomirski <luto@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
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>,
David Rientjes <rientjes@google.com>,
Cfir Cohen <cfir@google.com>, Erdem Aktas <erdemaktas@google.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mike Stunes <mstunes@vmware.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Martin Radev <martin.b.radev@gmail.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
virtualization@lists.linux-foundation.org
Subject: [PATCH v5 42/75] x86/sev-es: Setup GHCB based boot #VC handler
Date: Fri, 24 Jul 2020 18:03:03 +0200 [thread overview]
Message-ID: <20200724160336.5435-43-joro@8bytes.org> (raw)
In-Reply-To: <20200724160336.5435-1-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 | 6 ++
arch/x86/kernel/sev-es-shared.c | 14 ++--
arch/x86/kernel/sev-es.c | 116 ++++++++++++++++++++++++++++++++
arch/x86/mm/extable.c | 1 +
6 files changed, 132 insertions(+), 8 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 ec0e112a742b..824e9e6b067c 100644
--- a/arch/x86/include/asm/sev-es.h
+++ b/arch/x86/include/asm/sev-es.h
@@ -75,5 +75,6 @@ static inline u64 lower_bits(u64 val, unsigned int bits)
/* Early IDT entry points for #VC handler */
extern void vc_no_ghcb(void);
+extern bool handle_vc_boot_ghcb(struct pt_regs *regs);
#endif
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 250fae33bf66..ce2d8284edb9 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -403,6 +403,12 @@ void __init do_early_exception(struct pt_regs *regs, int trapnr)
early_make_pgtable(native_read_cr2()))
return;
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+ if (trapnr == X86_TRAP_VC &&
+ handle_vc_boot_ghcb(regs))
+ return;
+#endif
+
early_fixup_exception(regs, trapnr);
}
diff --git a/arch/x86/kernel/sev-es-shared.c b/arch/x86/kernel/sev-es-shared.c
index df6750aef3c8..4153b1b1048f 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 sev_es_terminate(unsigned int reason)
+static void sev_es_terminate(unsigned int reason)
{
u64 val = GHCB_SEV_TERMINATE;
@@ -27,7 +27,7 @@ static void __maybe_unused sev_es_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;
@@ -46,7 +46,7 @@ static bool __maybe_unused sev_es_negotiate_protocol(void)
return true;
}
-static void __maybe_unused vc_ghcb_invalidate(struct ghcb *ghcb)
+static void vc_ghcb_invalidate(struct ghcb *ghcb)
{
memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap));
}
@@ -58,9 +58,9 @@ static bool vc_decoding_needed(unsigned long exit_code)
exit_code <= SVM_EXIT_LAST_EXCP);
}
-static enum es_result __maybe_unused vc_init_em_ctxt(struct es_em_ctxt *ctxt,
- struct pt_regs *regs,
- unsigned long exit_code)
+static enum es_result vc_init_em_ctxt(struct es_em_ctxt *ctxt,
+ struct pt_regs *regs,
+ unsigned long exit_code)
{
enum es_result ret = ES_OK;
@@ -73,7 +73,7 @@ static enum es_result __maybe_unused vc_init_em_ctxt(struct es_em_ctxt *ctxt,
return ret;
}
-static void __maybe_unused vc_finish_insn(struct es_em_ctxt *ctxt)
+static void vc_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 0b698b653c0b..bb3e702a71eb 100644
--- a/arch/x86/kernel/sev-es.c
+++ b/arch/x86/kernel/sev-es.c
@@ -7,7 +7,9 @@
* 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/sev-es.h>
@@ -18,6 +20,18 @@
#include <asm/trapnr.h>
#include <asm/svm.h>
+/* For early boot hypervisor communication in SEV-ES enabled guests */
+static 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
+ */
+static struct ghcb __initdata *boot_ghcb;
+
+/* Needed in vc_early_forward_exception */
+void do_early_exception(struct pt_regs *regs, int trapnr);
+
static inline u64 sev_es_rd_ghcb_msr(void)
{
return native_read_msr(MSR_AMD64_SEV_ES_GHCB);
@@ -161,3 +175,105 @@ static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
/* 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 sev_es_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 vc_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;
+ do_early_exception(ctxt->regs, trapnr);
+}
+
+static enum es_result vc_handle_exitcode(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;
+}
+
+bool __init handle_vc_boot_ghcb(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 && !sev_es_setup_ghcb()))
+ sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
+
+ vc_ghcb_invalidate(boot_ghcb);
+
+ result = vc_init_em_ctxt(&ctxt, regs, exit_code);
+ if (result == ES_OK)
+ result = vc_handle_exitcode(&ctxt, boot_ghcb, exit_code);
+
+ /* Done - now check the result */
+ switch (result) {
+ case ES_OK:
+ vc_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:
+ vc_early_forward_exception(&ctxt);
+ break;
+ case ES_RETRY:
+ /* Nothing to do */
+ break;
+ default:
+ BUG();
+ }
+
+ return true;
+
+fail:
+ show_regs(regs);
+
+ while (true)
+ halt();
+}
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 1d6cb07f4f86..3966749d07ac 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>
--
2.27.0
next prev parent reply other threads:[~2020-07-24 16:07 UTC|newest]
Thread overview: 97+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-24 16:02 [PATCH v5 00/75] x86: SEV-ES Guest Support Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 01/75] KVM: SVM: Add GHCB definitions Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 02/75] KVM: SVM: Add GHCB Accessor functions Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 03/75] KVM: SVM: Use __packed shorthand Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 04/75] x86/cpufeatures: Add SEV-ES CPU feature Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 05/75] x86/traps: Move pf error codes to <asm/trap_pf.h> Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 06/75] x86/insn: Make inat-tables.c suitable for pre-decompression code Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 07/75] x86/umip: Factor out instruction fetch Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 08/75] x86/umip: Factor out instruction decoding Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 09/75] x86/insn: Add insn_get_modrm_reg_off() Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 10/75] x86/insn: Add insn_has_rep_prefix() helper Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 11/75] x86/boot/compressed/64: Disable red-zone usage Joerg Roedel
2020-07-24 17:43 ` Kees Cook
2020-07-24 17:58 ` Arvind Sankar
2020-07-24 16:02 ` [PATCH v5 12/75] x86/boot/compressed/64: Add IDT Infrastructure Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 13/75] x86/boot/compressed/64: Rename kaslr_64.c to ident_map_64.c Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 14/75] x86/boot/compressed/64: Add page-fault handler Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 15/75] x86/boot/compressed/64: Always switch to own page-table Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 16/75] x86/boot/compressed/64: Don't pre-map memory in KASLR code Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 17/75] x86/boot/compressed/64: Change add_identity_map() to take start and end Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 18/75] x86/boot/compressed/64: Add stage1 #VC handler Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 19/75] x86/boot/compressed/64: Call set_sev_encryption_mask earlier Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 20/75] x86/boot/compressed/64: Check return value of kernel_ident_mapping_init() Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 21/75] x86/boot/compressed/64: Add set_page_en/decrypted() helpers Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 22/75] x86/boot/compressed/64: Setup GHCB Based VC Exception handler Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 23/75] x86/boot/compressed/64: Unmap GHCB page before booting the kernel Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 24/75] x86/sev-es: Add support for handling IOIO exceptions Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 25/75] x86/fpu: Move xgetbv()/xsetbv() into separate header Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 26/75] x86/sev-es: Add CPUID handling to #VC handler Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 27/75] x86/idt: Move IDT to data segment Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 28/75] x86/idt: Split idt_data setup out of set_intr_gate() Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 29/75] x86/head/64: Install startup GDT Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 30/75] x86/head/64: Setup MSR_GS_BASE before calling into C code Joerg Roedel
2020-07-24 17:42 ` Kees Cook
2020-07-24 16:02 ` [PATCH v5 31/75] x86/head/64: Load GDT after switch to virtual addresses Joerg Roedel
2020-07-24 17:40 ` Kees Cook
2020-07-24 16:02 ` [PATCH v5 32/75] x86/head/64: Load segment registers earlier Joerg Roedel
2020-07-24 17:42 ` Kees Cook
2020-07-24 16:02 ` [PATCH v5 33/75] x86/head/64: Switch to initial stack earlier Joerg Roedel
2020-07-24 17:43 ` Kees Cook
2020-07-24 16:02 ` [PATCH v5 34/75] x86/head/64: Make fixup_pointer() static inline Joerg Roedel
2020-07-24 17:52 ` Kees Cook
2020-07-24 16:02 ` [PATCH v5 35/75] x86/head/64: Load IDT earlier Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 36/75] x86/head/64: Move early exception dispatch to C code Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 37/75] x86/head/64: Set CR4.FSGSBASE early Joerg Roedel
2020-07-24 16:02 ` [PATCH v5 38/75] x86/sev-es: Add SEV-ES Feature Detection Joerg Roedel
2020-07-24 17:54 ` Kees Cook
2020-07-24 16:03 ` [PATCH v5 39/75] x86/sev-es: Print SEV-ES info into kernel log Joerg Roedel
2020-07-24 17:54 ` Kees Cook
2020-07-24 16:03 ` [PATCH v5 40/75] x86/sev-es: Compile early handler code into kernel image Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 41/75] x86/sev-es: Setup early #VC handler Joerg Roedel
2020-07-24 16:03 ` Joerg Roedel [this message]
2020-07-24 16:03 ` [PATCH v5 43/75] x86/sev-es: Setup per-cpu GHCBs for the runtime handler Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 44/75] x86/sev-es: Allocate and Map IST stack for #VC handler Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 45/75] x86/sev-es: Adjust #VC IST Stack on entering NMI handler Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 46/75] x86/dumpstack/64: Add noinstr version of get_stack_info() Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 47/75] x86/entry/64: Add entry code for #VC handler Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 48/75] x86/sev-es: Add Runtime #VC Exception Handler Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 49/75] x86/sev-es: Wire up existing #VC exit-code handlers Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 50/75] x86/sev-es: Handle instruction fetches from user-space Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 51/75] x86/sev-es: Handle MMIO events Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 52/75] x86/sev-es: Handle MMIO String Instructions Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 53/75] x86/sev-es: Handle MSR events Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 54/75] x86/sev-es: Handle DR7 read/write events Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 55/75] x86/sev-es: Handle WBINVD Events Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 56/75] x86/sev-es: Handle RDTSC(P) Events Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 57/75] x86/sev-es: Handle RDPMC Events Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 58/75] x86/sev-es: Handle INVD Events Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 59/75] x86/sev-es: Handle MONITOR/MONITORX Events Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 60/75] x86/sev-es: Handle MWAIT/MWAITX Events Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 61/75] x86/sev-es: Handle VMMCALL Events Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 62/75] x86/sev-es: Handle #AC Events Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 63/75] x86/sev-es: Handle #DB Events Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 64/75] x86/paravirt: Allow hypervisor specific VMMCALL handling under SEV-ES Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 65/75] x86/kvm: Add KVM " Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 66/75] x86/vmware: Add VMware specific handling for VMMCALL " Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 67/75] x86/realmode: Add SEV-ES specific trampoline entry point Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 68/75] x86/realmode: Setup AP jump table Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 69/75] x86/smpboot: Setup TSS for starting AP Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 70/75] x86/head/64: Don't call verify_cpu() on starting APs Joerg Roedel
2020-07-24 17:57 ` Kees Cook
2020-07-24 16:03 ` [PATCH v5 71/75] x86/head/64: Rename start_cpu0 Joerg Roedel
2020-07-24 17:56 ` Kees Cook
2020-07-24 16:03 ` [PATCH v5 72/75] x86/sev-es: Support CPU offline/online Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 73/75] x86/sev-es: Handle NMI State Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 74/75] x86/efi: Add GHCB mappings when SEV-ES is active Joerg Roedel
2020-07-24 16:03 ` [PATCH v5 75/75] x86/sev-es: Check required CPU features for SEV-ES Joerg Roedel
2020-07-24 17:55 ` Kees Cook
2020-07-30 1:27 ` [PATCH v5 00/75] x86: SEV-ES Guest Support Mike Stunes
2020-07-30 12:26 ` Joerg Roedel
2020-07-30 23:23 ` Mike Stunes
2020-08-18 15:07 ` Joerg Roedel
2020-08-20 0:58 ` Mike Stunes
2020-08-20 12:10 ` Joerg Roedel
2020-08-21 8:05 ` Joerg Roedel
2020-08-21 17:42 ` Mike Stunes
2020-08-22 16:30 ` Joerg Roedel
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