LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Alexandre Chartre <alexandre.chartre@oracle.com>
To: pbonzini@redhat.com, rkrcmar@redhat.com, tglx@linutronix.de,
	mingo@redhat.com, bp@alien8.de, hpa@zytor.com,
	dave.hansen@linux.intel.com, luto@kernel.org,
	peterz@infradead.org, kvm@vger.kernel.org, x86@kernel.org,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc: konrad.wilk@oracle.com, jan.setjeeilers@oracle.com,
	liran.alon@oracle.com, jwadams@google.com,
	alexandre.chartre@oracle.com
Subject: [RFC KVM 03/27] KVM: x86: Introduce KVM separate virtual address space
Date: Mon, 13 May 2019 16:38:11 +0200	[thread overview]
Message-ID: <1557758315-12667-4-git-send-email-alexandre.chartre@oracle.com> (raw)
In-Reply-To: <1557758315-12667-1-git-send-email-alexandre.chartre@oracle.com>

From: Liran Alon <liran.alon@oracle.com>

Create a separate mm for KVM that will be active when KVM #VMExit
handlers run. Up until the point which we architectully need to
access host (or other VM) sensitive data.

This patch just create kvm_mm but never makes it active yet.
This will be done by next commits.

Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
---
 arch/x86/kvm/isolation.c |   95 ++++++++++++++++++++++++++++++++++++++++++++++
 arch/x86/kvm/isolation.h |    8 ++++
 arch/x86/kvm/x86.c       |   10 ++++-
 3 files changed, 112 insertions(+), 1 deletions(-)
 create mode 100644 arch/x86/kvm/isolation.h

diff --git a/arch/x86/kvm/isolation.c b/arch/x86/kvm/isolation.c
index e25f663..74bc0cd 100644
--- a/arch/x86/kvm/isolation.c
+++ b/arch/x86/kvm/isolation.c
@@ -7,6 +7,21 @@
 
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/printk.h>
+
+#include <asm/mmu_context.h>
+#include <asm/pgalloc.h>
+
+#include "isolation.h"
+
+struct mm_struct kvm_mm = {
+	.mm_rb			= RB_ROOT,
+	.mm_users		= ATOMIC_INIT(2),
+	.mm_count		= ATOMIC_INIT(1),
+	.mmap_sem		= __RWSEM_INITIALIZER(kvm_mm.mmap_sem),
+	.page_table_lock	= __SPIN_LOCK_UNLOCKED(kvm_mm.page_table_lock),
+	.mmlist			= LIST_HEAD_INIT(kvm_mm.mmlist),
+};
 
 /*
  * When set to true, KVM #VMExit handlers run in isolated address space
@@ -24,3 +39,83 @@
  */
 static bool __read_mostly address_space_isolation;
 module_param(address_space_isolation, bool, 0444);
+
+static int kvm_isolation_init_mm(void)
+{
+	pgd_t *kvm_pgd;
+	gfp_t gfp_mask;
+
+	gfp_mask = GFP_KERNEL | __GFP_ZERO;
+	kvm_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
+	if (!kvm_pgd)
+		return -ENOMEM;
+
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
+	/*
+	 * With PTI, we have two PGDs: one the kernel page table, and one
+	 * for the user page table. The PGD with the kernel page table has
+	 * to be the entire kernel address space because paranoid faults
+	 * will unconditionally use it. So we define the KVM address space
+	 * in the user table space, although it will be used in the kernel.
+	 */
+
+	/* initialize the kernel page table */
+	memcpy(kvm_pgd, current->active_mm->pgd, sizeof(pgd_t) * PTRS_PER_PGD);
+
+	/* define kvm_mm with the user page table */
+	kvm_mm.pgd = kernel_to_user_pgdp(kvm_pgd);
+#else /* CONFIG_PAGE_TABLE_ISOLATION */
+	kvm_mm.pgd = kvm_pgd;
+#endif /* CONFIG_PAGE_TABLE_ISOLATION */
+	mm_init_cpumask(&kvm_mm);
+	init_new_context(NULL, &kvm_mm);
+
+	return 0;
+}
+
+static void kvm_isolation_uninit_mm(void)
+{
+	pgd_t *kvm_pgd;
+
+	BUG_ON(current->active_mm == &kvm_mm);
+
+	destroy_context(&kvm_mm);
+
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
+	/*
+	 * With PTI, the KVM address space is defined in the user
+	 * page table space, but the full PGD starts with the kernel
+	 * page table space.
+	 */
+	kvm_pgd = user_to_kernel_pgdp(kvm_pgd);
+#else /* CONFIG_PAGE_TABLE_ISOLATION */
+	kvm_pgd = kvm_mm.pgd;
+#endif /* CONFIG_PAGE_TABLE_ISOLATION */
+	kvm_mm.pgd = NULL;
+	free_pages((unsigned long)kvm_pgd, PGD_ALLOCATION_ORDER);
+}
+
+int kvm_isolation_init(void)
+{
+	int r;
+
+	if (!address_space_isolation)
+		return 0;
+
+	r = kvm_isolation_init_mm();
+	if (r)
+		return r;
+
+	pr_info("KVM: x86: Running with isolated address space\n");
+
+	return 0;
+}
+
+void kvm_isolation_uninit(void)
+{
+	if (!address_space_isolation)
+		return;
+
+	kvm_isolation_uninit_mm();
+	pr_info("KVM: x86: End of isolated address space\n");
+}
diff --git a/arch/x86/kvm/isolation.h b/arch/x86/kvm/isolation.h
new file mode 100644
index 0000000..cf8c7d4
--- /dev/null
+++ b/arch/x86/kvm/isolation.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ARCH_X86_KVM_ISOLATION_H
+#define ARCH_X86_KVM_ISOLATION_H
+
+extern int kvm_isolation_init(void);
+extern void kvm_isolation_uninit(void);
+
+#endif
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b5edc8e..4b7cec2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -29,6 +29,7 @@
 #include "cpuid.h"
 #include "pmu.h"
 #include "hyperv.h"
+#include "isolation.h"
 
 #include <linux/clocksource.h>
 #include <linux/interrupt.h>
@@ -6972,10 +6973,14 @@ int kvm_arch_init(void *opaque)
 		goto out_free_x86_fpu_cache;
 	}
 
-	r = kvm_mmu_module_init();
+	r = kvm_isolation_init();
 	if (r)
 		goto out_free_percpu;
 
+	r = kvm_mmu_module_init();
+	if (r)
+		goto out_uninit_isolation;
+
 	kvm_set_mmio_spte_mask();
 
 	kvm_x86_ops = ops;
@@ -7000,6 +7005,8 @@ int kvm_arch_init(void *opaque)
 
 	return 0;
 
+out_uninit_isolation:
+	kvm_isolation_uninit();
 out_free_percpu:
 	free_percpu(shared_msrs);
 out_free_x86_fpu_cache:
@@ -7024,6 +7031,7 @@ void kvm_arch_exit(void)
 #ifdef CONFIG_X86_64
 	pvclock_gtod_unregister_notifier(&pvclock_gtod_notifier);
 #endif
+	kvm_isolation_uninit();
 	kvm_x86_ops = NULL;
 	kvm_mmu_module_exit();
 	free_percpu(shared_msrs);
-- 
1.7.1


  parent reply	other threads:[~2019-05-13 14:39 UTC|newest]

Thread overview: 86+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-13 14:38 [RFC KVM 00/27] KVM Address Space Isolation Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 01/27] kernel: Export memory-management symbols required for KVM address space isolation Alexandre Chartre
2019-05-13 15:15   ` Peter Zijlstra
2019-05-13 15:17     ` Liran Alon
2019-05-13 14:38 ` [RFC KVM 02/27] KVM: x86: Introduce address_space_isolation module parameter Alexandre Chartre
2019-05-13 15:46   ` Andy Lutomirski
2019-05-13 15:55     ` Alexandre Chartre
2019-05-13 14:38 ` Alexandre Chartre [this message]
2019-05-13 15:45   ` [RFC KVM 03/27] KVM: x86: Introduce KVM separate virtual address space Andy Lutomirski
2019-05-13 16:04     ` Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 04/27] KVM: x86: Switch to KVM address space on entry to guest Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 05/27] KVM: x86: Add handler to exit kvm isolation Alexandre Chartre
2019-05-13 15:49   ` Andy Lutomirski
2019-05-13 16:10     ` Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 06/27] KVM: x86: Exit KVM isolation on IRQ entry Alexandre Chartre
2019-05-13 15:51   ` Andy Lutomirski
2019-05-13 16:28     ` Alexandre Chartre
2019-05-13 18:13       ` Andy Lutomirski
2019-05-14  7:07         ` Peter Zijlstra
2019-05-14  7:58           ` Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 07/27] KVM: x86: Switch to host address space when may access sensitive data Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 08/27] KVM: x86: Optimize branches which checks if address space isolation enabled Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 09/27] kvm/isolation: function to track buffers allocated for the KVM page table Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 10/27] kvm/isolation: add KVM page table entry free functions Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 11/27] kvm/isolation: add KVM page table entry offset functions Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 12/27] kvm/isolation: add KVM page table entry allocation functions Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 13/27] kvm/isolation: add KVM page table entry set functions Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 14/27] kvm/isolation: functions to copy page table entries for a VA range Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 15/27] kvm/isolation: keep track of VA range mapped in KVM address space Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 16/27] kvm/isolation: functions to clear page table entries for a VA range Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 17/27] kvm/isolation: improve mapping copy when mapping is already present Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 18/27] kvm/isolation: function to copy page table entries for percpu buffer Alexandre Chartre
2019-05-13 18:18   ` Andy Lutomirski
2019-05-14  7:09     ` Peter Zijlstra
2019-05-14  8:25       ` Alexandre Chartre
2019-05-14  8:34         ` Andy Lutomirski
2019-05-14  9:41           ` Alexandre Chartre
2019-05-14 15:23             ` Andy Lutomirski
2019-05-14 16:24               ` Alexandre Chartre
2019-05-14 17:05                 ` Peter Zijlstra
2019-05-14 18:09                   ` Sean Christopherson
2019-05-14 20:33                     ` Andy Lutomirski
2019-05-14 21:06                       ` Sean Christopherson
2019-05-14 21:55                         ` Andy Lutomirski
2019-05-14 22:38                           ` Sean Christopherson
2019-05-18  0:05                             ` Jonathan Adams
2019-05-14 20:27                   ` Andy Lutomirski
2019-05-13 14:38 ` [RFC KVM 19/27] kvm/isolation: initialize the KVM page table with core mappings Alexandre Chartre
2019-05-13 15:50   ` Dave Hansen
2019-05-13 16:00     ` Andy Lutomirski
2019-05-13 17:00       ` Alexandre Chartre
2019-05-13 16:46     ` Sean Christopherson
2019-05-13 16:47     ` Alexandre Chartre
2019-05-14 10:26       ` Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 20/27] kvm/isolation: initialize the KVM page table with vmx specific data Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 21/27] kvm/isolation: initialize the KVM page table with vmx VM data Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 22/27] kvm/isolation: initialize the KVM page table with vmx cpu data Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 23/27] kvm/isolation: initialize the KVM page table with the vcpu tasks Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 24/27] kvm/isolation: KVM page fault handler Alexandre Chartre
2019-05-13 15:15   ` Peter Zijlstra
2019-05-13 21:25     ` Liran Alon
2019-05-14  2:02       ` Andy Lutomirski
2019-05-14  7:21         ` Peter Zijlstra
2019-05-14 15:36           ` Alexandre Chartre
2019-05-14 15:43             ` Andy Lutomirski
2019-05-13 16:02   ` Andy Lutomirski
2019-05-13 16:21     ` Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 25/27] kvm/isolation: implement actual KVM isolation enter/exit Alexandre Chartre
2019-05-13 15:16   ` Peter Zijlstra
2019-05-13 16:01   ` Andy Lutomirski
2019-05-13 14:38 ` [RFC KVM 26/27] kvm/isolation: initialize the KVM page table with KVM memslots Alexandre Chartre
2019-05-13 14:38 ` [RFC KVM 27/27] kvm/isolation: initialize the KVM page table with KVM buses Alexandre Chartre
2019-05-13 16:42 ` [RFC KVM 00/27] KVM Address Space Isolation Liran Alon
2019-05-13 18:17 ` Andy Lutomirski
2019-05-13 21:08   ` Liran Alon
2019-05-14  2:07     ` Andy Lutomirski
2019-05-14  7:37       ` Peter Zijlstra
2019-05-14 21:32         ` Jan Setje-Eilers
2019-05-14  8:05       ` Liran Alon
2019-05-14  7:29     ` Peter Zijlstra
2019-05-14  7:57       ` Liran Alon
2019-05-14  8:33     ` Alexandre Chartre
2019-05-13 19:31 ` Nakajima, Jun
2019-05-13 21:16   ` Liran Alon
     [not found]     ` <D07C8F51-F2DF-4C8B-AB3B-0DFABD5F4C33@intel.com>
2019-05-13 21:53       ` Liran Alon
2019-05-15 12:52 ` Alexandre Chartre

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1557758315-12667-4-git-send-email-alexandre.chartre@oracle.com \
    --to=alexandre.chartre@oracle.com \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=hpa@zytor.com \
    --cc=jan.setjeeilers@oracle.com \
    --cc=jwadams@google.com \
    --cc=konrad.wilk@oracle.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=liran.alon@oracle.com \
    --cc=luto@kernel.org \
    --cc=mingo@redhat.com \
    --cc=pbonzini@redhat.com \
    --cc=peterz@infradead.org \
    --cc=rkrcmar@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    --subject='Re: [RFC KVM 03/27] KVM: x86: Introduce KVM separate virtual address space' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).