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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 15/70] x86/boot/compressed/64: Always switch to own page-table
Date: Thu, 19 Mar 2020 10:13:12 +0100	[thread overview]
Message-ID: <20200319091407.1481-16-joro@8bytes.org> (raw)
In-Reply-To: <20200319091407.1481-1-joro@8bytes.org>

From: Joerg Roedel <jroedel@suse.de>

When booted through startup_64 the kernel keeps running on the EFI
page-table until the KASLR code sets up its own page-table. Without
KASLR the pre-decompression boot code never switches off the EFI
page-table. Change that by unconditionally switching to our own
page-table once the kernel is relocated.

This makes sure we can make changes to the mapping when necessary, for
example map pages unencrypted in SEV and SEV-ES guests.

Also remove the debug_putstr() calls in initialize_identity_maps()
because the function now runs before console_init() is called.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 arch/x86/boot/compressed/head_64.S      |  3 +-
 arch/x86/boot/compressed/ident_map_64.c | 51 +++++++++++++++----------
 arch/x86/boot/compressed/kaslr.c        |  3 --
 3 files changed, 32 insertions(+), 25 deletions(-)

diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index d27a9ce1bcb0..5164d2e8631a 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -491,10 +491,11 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated)
 	rep	stosq
 
 /*
- * Load stage2 IDT
+ * Load stage2 IDT and switch to our own page-table
  */
 	pushq	%rsi
 	call	load_stage2_idt
+	call	initialize_identity_maps
 	popq	%rsi
 
 /*
diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c
index 0865d181b85d..6a3890caaa19 100644
--- a/arch/x86/boot/compressed/ident_map_64.c
+++ b/arch/x86/boot/compressed/ident_map_64.c
@@ -88,9 +88,31 @@ phys_addr_t physical_mask = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
  */
 static struct x86_mapping_info mapping_info;
 
+/*
+ * Adds the specified range to what will become the new identity mappings.
+ * Once all ranges have been added, the new mapping is activated by calling
+ * finalize_identity_maps() below.
+ */
+void add_identity_map(unsigned long start, unsigned long size)
+{
+	unsigned long end = start + size;
+
+	/* Align boundary to 2M. */
+	start = round_down(start, PMD_SIZE);
+	end = round_up(end, PMD_SIZE);
+	if (start >= end)
+		return;
+
+	/* Build the mapping. */
+	kernel_ident_mapping_init(&mapping_info, (pgd_t *)top_level_pgt,
+				  start, end);
+}
+
 /* Locates and clears a region for a new top level page table. */
 void initialize_identity_maps(void)
 {
+	unsigned long start, size;
+
 	/* If running as an SEV guest, the encryption mask is required. */
 	set_sev_encryption_mask();
 
@@ -123,37 +145,24 @@ void initialize_identity_maps(void)
 	 */
 	top_level_pgt = read_cr3_pa();
 	if (p4d_offset((pgd_t *)top_level_pgt, 0) == (p4d_t *)_pgtable) {
-		debug_putstr("booted via startup_32()\n");
 		pgt_data.pgt_buf = _pgtable + BOOT_INIT_PGT_SIZE;
 		pgt_data.pgt_buf_size = BOOT_PGT_SIZE - BOOT_INIT_PGT_SIZE;
 		memset(pgt_data.pgt_buf, 0, pgt_data.pgt_buf_size);
 	} else {
-		debug_putstr("booted via startup_64()\n");
 		pgt_data.pgt_buf = _pgtable;
 		pgt_data.pgt_buf_size = BOOT_PGT_SIZE;
 		memset(pgt_data.pgt_buf, 0, pgt_data.pgt_buf_size);
 		top_level_pgt = (unsigned long)alloc_pgt_page(&pgt_data);
 	}
-}
 
-/*
- * Adds the specified range to what will become the new identity mappings.
- * Once all ranges have been added, the new mapping is activated by calling
- * finalize_identity_maps() below.
- */
-void add_identity_map(unsigned long start, unsigned long size)
-{
-	unsigned long end = start + size;
-
-	/* Align boundary to 2M. */
-	start = round_down(start, PMD_SIZE);
-	end = round_up(end, PMD_SIZE);
-	if (start >= end)
-		return;
-
-	/* Build the mapping. */
-	kernel_ident_mapping_init(&mapping_info, (pgd_t *)top_level_pgt,
-				  start, end);
+	/*
+	 * New page-table is set up - map the kernel image and load it
+	 * into cr3.
+	 */
+	start = (unsigned long)_head;
+	size  = _end - _head;
+	add_identity_map(start, size);
+	write_cr3(top_level_pgt);
 }
 
 /*
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index 7c61a8c5b9cf..856dc1c9bb0d 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -903,9 +903,6 @@ void choose_random_location(unsigned long input,
 
 	boot_params->hdr.loadflags |= KASLR_FLAG;
 
-	/* Prepare to add new identity pagetables on demand. */
-	initialize_identity_maps();
-
 	/* Record the various known unsafe memory ranges. */
 	mem_avoid_init(input, input_size, *output);
 
-- 
2.17.1


  parent reply	other threads:[~2020-03-19  9:14 UTC|newest]

Thread overview: 181+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-19  9:12 [RFC PATCH 00/70 v2] x86: SEV-ES Guest Support Joerg Roedel
2020-03-19  9:12 ` [PATCH 01/70] KVM: SVM: Add GHCB definitions Joerg Roedel
2020-03-23 13:23   ` [PATCH] KVM: SVM: Use __packed shorthard Borislav Petkov
2020-03-24 12:43     ` Joerg Roedel
2020-03-19  9:12 ` [PATCH 02/70] KVM: SVM: Add GHCB Accessor functions Joerg Roedel
2020-03-19  9:13 ` [PATCH 03/70] x86/cpufeatures: Add SEV-ES CPU feature Joerg Roedel
2020-03-19  9:13 ` [PATCH 04/70] x86/traps: Move some definitions to <asm/trap_defs.h> Joerg Roedel
2020-03-19  9:13 ` [PATCH 05/70] x86/insn: Make inat-tables.c suitable for pre-decompression code Joerg Roedel
2020-03-25 15:39   ` Borislav Petkov
2020-03-27  3:02     ` Masami Hiramatsu
2020-04-16 15:24       ` Joerg Roedel
2020-04-17 12:50         ` Masami Hiramatsu
2020-04-17 13:39           ` Joerg Roedel
2020-03-19  9:13 ` [PATCH 06/70] x86/umip: Factor out instruction fetch Joerg Roedel
2020-03-26 17:21   ` Borislav Petkov
2020-03-19  9:13 ` [PATCH 07/70] x86/umip: Factor out instruction decoding Joerg Roedel
2020-03-26 17:24   ` Borislav Petkov
2020-03-19  9:13 ` [PATCH 08/70] x86/insn: Add insn_get_modrm_reg_off() Joerg Roedel
2020-03-27  3:57   ` Masami Hiramatsu
2020-03-19  9:13 ` [PATCH 09/70] x86/insn: Add insn_rep_prefix() helper Joerg Roedel
2020-03-27  3:56   ` Masami Hiramatsu
2020-03-19  9:13 ` [PATCH 10/70] x86/boot/compressed: Fix debug_puthex() parameter type Joerg Roedel
2020-03-28 11:23   ` [tip: x86/boot] " tip-bot2 for Joerg Roedel
2020-03-19  9:13 ` [PATCH 11/70] x86/boot/compressed/64: Disable red-zone usage Joerg Roedel
2020-03-31 13:16   ` Borislav Petkov
2020-03-19  9:13 ` [PATCH 12/70] x86/boot/compressed/64: Add IDT Infrastructure Joerg Roedel
2020-04-07  2:21   ` Arvind Sankar
2020-04-16 13:30     ` Joerg Roedel
2020-03-19  9:13 ` [PATCH 13/70] x86/boot/compressed/64: Rename kaslr_64.c to ident_map_64.c Joerg Roedel
2020-03-19  9:13 ` [PATCH 14/70] x86/boot/compressed/64: Add page-fault handler Joerg Roedel
2020-04-02 11:49   ` Borislav Petkov
2020-03-19  9:13 ` Joerg Roedel [this message]
2020-04-06 11:56   ` [PATCH 15/70] x86/boot/compressed/64: Always switch to own page-table Borislav Petkov
2020-03-19  9:13 ` [PATCH 16/70] x86/boot/compressed/64: Don't pre-map memory in KASLR code Joerg Roedel
2020-03-19  9:13 ` [PATCH 17/70] x86/boot/compressed/64: Change add_identity_map() to take start and end Joerg Roedel
2020-03-19  9:13 ` [PATCH 18/70] x86/boot/compressed/64: Add stage1 #VC handler Joerg Roedel
2020-03-20 21:16   ` David Rientjes
2020-03-20 22:19     ` Joerg Roedel
2020-04-06 12:41   ` Borislav Petkov
2020-03-19  9:13 ` [PATCH 19/70] x86/boot/compressed/64: Call set_sev_encryption_mask earlier Joerg Roedel
2020-03-19  9:13 ` [PATCH 20/70] x86/boot/compressed/64: Check return value of kernel_ident_mapping_init() Joerg Roedel
2020-03-19  9:13 ` [PATCH 21/70] x86/boot/compressed/64: Add function to map a page unencrypted Joerg Roedel
2020-03-20 20:53   ` David Rientjes
2020-03-20 21:02     ` Dave Hansen
2020-03-20 22:12       ` Joerg Roedel
2020-03-20 22:26         ` Dave Hansen
2020-03-21 15:40           ` Joerg Roedel
2020-03-19  9:13 ` [PATCH 22/70] x86/boot/compressed/64: Setup GHCB Based VC Exception handler Joerg Roedel
2020-03-19  9:13 ` [PATCH 23/70] x86/sev-es: Add support for handling IOIO exceptions Joerg Roedel
2020-03-20 21:03   ` David Rientjes
2020-03-20 22:24     ` Joerg Roedel
2020-03-19  9:13 ` [PATCH 24/70] x86/fpu: Move xgetbv()/xsetbv() into separate header Joerg Roedel
2020-03-19  9:13 ` [PATCH 25/70] x86/sev-es: Add CPUID handling to #VC handler Joerg Roedel
2020-03-19  9:13 ` [PATCH 26/70] x86/idt: Move IDT to data segment Joerg Roedel
2020-03-19  9:13 ` [PATCH 27/70] x86/idt: Split idt_data setup out of set_intr_gate() Joerg Roedel
2020-03-19  9:13 ` [PATCH 28/70] x86/idt: Move two function from k/idt.c to i/a/desc.h Joerg Roedel
2020-03-19  9:13 ` [PATCH 29/70] x86/head/64: Install boot GDT Joerg Roedel
2020-03-19  9:13 ` [PATCH 30/70] x86/head/64: Reload GDT after switch to virtual addresses Joerg Roedel
2020-03-19  9:13 ` [PATCH 31/70] x86/head/64: Load segment registers earlier Joerg Roedel
2020-03-19  9:13 ` [PATCH 32/70] x86/head/64: Switch to initial stack earlier Joerg Roedel
2020-03-19  9:13 ` [PATCH 33/70] x86/head/64: Build k/head64.c with -fno-stack-protector Joerg Roedel
2020-03-19  9:13 ` [PATCH 34/70] x86/head/64: Load IDT earlier Joerg Roedel
2020-03-19  9:13 ` [PATCH 35/70] x86/head/64: Move early exception dispatch to C code Joerg Roedel
2020-03-19  9:13 ` [PATCH 36/70] x86/sev-es: Add SEV-ES Feature Detection Joerg Roedel
2020-03-19  9:13 ` [PATCH 37/70] x86/sev-es: Compile early handler code into kernel image Joerg Roedel
2020-03-19  9:13 ` [PATCH 38/70] x86/sev-es: Setup early #VC handler Joerg Roedel
2020-03-19  9:13 ` [PATCH 39/70] x86/sev-es: Setup GHCB based boot " Joerg Roedel
2020-03-19  9:13 ` [PATCH 40/70] x86/sev-es: Setup per-cpu GHCBs for the runtime handler Joerg Roedel
2020-04-14 19:03   ` Mike Stunes
2020-04-14 20:04     ` Tom Lendacky
2020-04-14 20:12       ` Dave Hansen
2020-04-14 20:16         ` Tom Lendacky
2020-04-14 20:18           ` Tom Lendacky
2020-04-15 15:54       ` Joerg Roedel
2020-04-15 15:53     ` Joerg Roedel
2020-04-23  1:33       ` Bo Gan
2020-04-23 11:30         ` Joerg Roedel
2020-03-19  9:13 ` [PATCH 41/70] x86/sev-es: Add Runtime #VC Exception Handler Joerg Roedel
2020-03-19 15:44   ` Andy Lutomirski
2020-03-19 16:24     ` Joerg Roedel
2020-03-19 18:43       ` Andy Lutomirski
2020-03-19 19:38         ` Joerg Roedel
2020-03-19  9:13 ` [PATCH 42/70] x86/sev-es: Support nested #VC exceptions Joerg Roedel
2020-03-19 15:46   ` Andy Lutomirski
2020-03-19 16:12     ` Joerg Roedel
2020-03-19  9:13 ` [PATCH 43/70] x86/sev-es: Wire up existing #VC exit-code handlers Joerg Roedel
2020-03-19  9:13 ` [PATCH 44/70] x86/sev-es: Handle instruction fetches from user-space Joerg Roedel
2020-03-19  9:13 ` [PATCH 45/70] x86/sev-es: Harden runtime #VC handler for exceptions " Joerg Roedel
2020-03-19  9:13 ` [PATCH 46/70] x86/sev-es: Filter exceptions not supported " Joerg Roedel
2020-03-19  9:13 ` [PATCH 47/70] x86/sev-es: Handle MMIO events Joerg Roedel
2020-03-19  9:13 ` [PATCH 48/70] x86/sev-es: Handle MMIO String Instructions Joerg Roedel
2020-03-19  9:13 ` [PATCH 49/70] x86/sev-es: Handle MSR events Joerg Roedel
2020-03-19  9:13 ` [PATCH 50/70] x86/sev-es: Handle DR7 read/write events Joerg Roedel
2020-03-19  9:13 ` [PATCH 51/70] x86/sev-es: Handle WBINVD Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 52/70] x86/sev-es: Handle RDTSC Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 53/70] x86/sev-es: Handle RDPMC Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 54/70] x86/sev-es: Handle INVD Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 55/70] x86/sev-es: Handle RDTSCP Events Joerg Roedel
2020-04-24 21:03   ` [PATCH] Allow RDTSC and RDTSCP from userspace Mike Stunes
2020-04-24 21:24     ` Dave Hansen
2020-04-24 21:27       ` Tom Lendacky
2020-04-24 22:53         ` Dave Hansen
2020-04-25 12:49           ` Joerg Roedel
2020-04-25 18:15             ` Andy Lutomirski
2020-04-25 19:10               ` Joerg Roedel
2020-04-25 19:47                 ` Andy Lutomirski
2020-04-25 20:23                   ` Joerg Roedel
2020-04-25 22:10                     ` Andy Lutomirski
2020-04-27 17:37                       ` Should SEV-ES #VC use IST? (Re: [PATCH] Allow RDTSC and RDTSCP from userspace) Andy Lutomirski
2020-04-27 18:15                         ` Andrew Cooper
2020-04-27 18:43                         ` Tom Lendacky
2020-04-28  7:55                         ` Joerg Roedel
2020-04-28 16:34                           ` Andrew Cooper
2020-06-23 11:07                           ` Peter Zijlstra
2020-06-23 11:30                             ` Joerg Roedel
2020-06-23 11:48                               ` Peter Zijlstra
2020-06-23 12:04                                 ` Joerg Roedel
2020-06-23 12:52                                   ` Peter Zijlstra
2020-06-23 13:40                                     ` Joerg Roedel
2020-06-23 13:59                                       ` Peter Zijlstra
2020-06-23 14:53                                         ` Peter Zijlstra
2020-06-23 14:59                                           ` Joerg Roedel
2020-06-23 15:23                                             ` Peter Zijlstra
2020-06-23 15:38                                               ` Peter Zijlstra
2020-06-23 15:38                                               ` Joerg Roedel
2020-06-23 16:02                                                 ` Peter Zijlstra
2020-06-23 15:39                                               ` Andrew Cooper
2020-06-23 15:52                                                 ` Peter Zijlstra
2020-06-23 16:03                                                   ` Dave Hansen
2020-06-23 16:13                                                     ` Peter Zijlstra
2020-06-23 16:13                                                 ` Borislav Petkov
2020-06-23 11:51                               ` Andrew Cooper
2020-06-23 12:47                                 ` Peter Zijlstra
2020-06-23 13:57                                   ` Andrew Cooper
2020-06-23 15:51                                 ` Borislav Petkov
2020-06-23  9:45                         ` Joerg Roedel
2020-06-23 10:45                           ` Peter Zijlstra
2020-06-23 11:11                             ` Joerg Roedel
2020-06-23 11:14                               ` Peter Zijlstra
2020-06-23 11:43                                 ` Joerg Roedel
2020-06-23 11:50                                   ` Peter Zijlstra
2020-06-23 12:12                                     ` Joerg Roedel
2020-06-23 13:03                                       ` Peter Zijlstra
2020-06-23 14:49                                         ` Joerg Roedel
2020-06-23 15:16                                           ` Peter Zijlstra
2020-06-23 15:32                                             ` Andrew Cooper
2020-06-23 16:10                                               ` Borislav Petkov
2020-06-23 15:22                                         ` Andrew Cooper
2020-06-23 18:26                                           ` Andy Lutomirski
2020-06-23 18:56                                             ` Andrew Cooper
2020-04-27 18:47             ` [PATCH] Allow RDTSC and RDTSCP from userspace Dave Hansen
2020-04-25 12:28     ` Joerg Roedel
2020-03-19  9:13 ` [PATCH 56/70] x86/sev-es: Handle MONITOR/MONITORX Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 57/70] x86/sev-es: Handle MWAIT/MWAITX Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 58/70] x86/sev-es: Handle VMMCALL Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 59/70] x86/sev-es: Handle #AC Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 60/70] x86/sev-es: Handle #DB Events Joerg Roedel
2020-03-19  9:13 ` [PATCH 61/70] x86/paravirt: Allow hypervisor specific VMMCALL handling under SEV-ES Joerg Roedel
2020-03-19  9:13 ` [PATCH 62/70] x86/kvm: Add KVM " Joerg Roedel
2020-03-20 21:23   ` David Rientjes
2020-03-20 22:21     ` Joerg Roedel
2020-03-19  9:14 ` [PATCH 63/70] x86/vmware: Add VMware specific handling for VMMCALL " Joerg Roedel
2020-03-19 10:18   ` Thomas Hellstrom
2020-03-19  9:14 ` [PATCH 64/70] x86/realmode: Add SEV-ES specific trampoline entry point Joerg Roedel
2020-03-19  9:14 ` [PATCH 65/70] x86/realmode: Setup AP jump table Joerg Roedel
2020-03-19  9:14 ` [PATCH 66/70] x86/head/64: Don't call verify_cpu() on starting APs Joerg Roedel
2020-03-19  9:14 ` [PATCH 67/70] x86/head/64: Rename start_cpu0 Joerg Roedel
2020-03-19  9:14 ` [PATCH 68/70] x86/sev-es: Support CPU offline/online Joerg Roedel
2020-03-19  9:14 ` [PATCH 69/70] x86/cpufeature: Add SEV_ES_GUEST CPU Feature Joerg Roedel
2020-03-19  9:14 ` [PATCH 70/70] x86/sev-es: Add NMI state tracking Joerg Roedel
2020-03-19 15:35   ` Andy Lutomirski
2020-03-19 16:07     ` Joerg Roedel
2020-03-19 18:40       ` Andy Lutomirski
2020-03-19 19:26         ` Joerg Roedel
2020-03-19 21:27           ` Andy Lutomirski
2020-03-20 19:48             ` Joerg Roedel
2020-03-20 13:17     ` [RFC PATCH v2.1] x86/sev-es: Handle NMI State Joerg Roedel
2020-03-20 14:42       ` Dave Hansen
2020-03-20 19:42         ` Joerg Roedel
2020-03-19 16:53   ` [PATCH 70/70] x86/sev-es: Add NMI state tracking Mika Penttilä
2020-03-19 19:41     ` Joerg Roedel

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