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From: Quentin Perret <qperret@google.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,  Marc Zyngier <maz@kernel.org>,
	James Morse <james.morse@arm.com>,
	 Julien Thierry <julien.thierry.kdev@gmail.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	 Rob Herring <robh+dt@kernel.org>,
	Frank Rowand <frowand.list@gmail.com>
Cc: "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE"
	<devicetree@vger.kernel.org>,
	android-kvm@google.com, open list <linux-kernel@vger.kernel.org>,
	kernel-team@android.com,
	"open list:KERNEL VIRTUAL MACHINE FOR ARM64 \(KVM/arm64\)"
	<kvmarm@lists.cs.columbia.edu>,
	"moderated list:ARM64 PORT \(AARCH64 ARCHITECTURE\)"
	<linux-arm-kernel@lists.infradead.org>
Subject: [RFC PATCH 10/27] KVM: arm64: Introduce an early Hyp page allocator
Date: Tue, 17 Nov 2020 18:15:50 +0000	[thread overview]
Message-ID: <20201117181607.1761516-11-qperret@google.com> (raw)
In-Reply-To: <20201117181607.1761516-1-qperret@google.com>

With nVHE, the host currently creates all s1 hypervisor mappings at EL1
during boot, installs them at EL2, and extends them as required (e.g.
when creating a new VM). But in a world where the host is no longer
trusted, it cannot have full control over the code mapped in the
hypervisor.

In preparation for enabling the hypervisor to create its own s1 mappings
during boot, introduce an early page allocator, with minimal
functionality. This allocator is designed to be used only during early
bootstrap of the hyp code when memory protection is enabled, which will
then switch to using a full-fledged page allocator after init.

Signed-off-by: Quentin Perret <qperret@google.com>
---
 arch/arm64/kvm/hyp/include/nvhe/early_alloc.h | 14 +++++
 arch/arm64/kvm/hyp/include/nvhe/memory.h      | 24 ++++++++
 arch/arm64/kvm/hyp/nvhe/Makefile              |  2 +-
 arch/arm64/kvm/hyp/nvhe/early_alloc.c         | 60 +++++++++++++++++++
 arch/arm64/kvm/hyp/nvhe/psci-relay.c          |  5 +-
 5 files changed, 101 insertions(+), 4 deletions(-)
 create mode 100644 arch/arm64/kvm/hyp/include/nvhe/early_alloc.h
 create mode 100644 arch/arm64/kvm/hyp/include/nvhe/memory.h
 create mode 100644 arch/arm64/kvm/hyp/nvhe/early_alloc.c

diff --git a/arch/arm64/kvm/hyp/include/nvhe/early_alloc.h b/arch/arm64/kvm/hyp/include/nvhe/early_alloc.h
new file mode 100644
index 000000000000..68ce2bf9a718
--- /dev/null
+++ b/arch/arm64/kvm/hyp/include/nvhe/early_alloc.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __KVM_HYP_EARLY_ALLOC_H
+#define __KVM_HYP_EARLY_ALLOC_H
+
+#include <asm/kvm_pgtable.h>
+
+void hyp_early_alloc_init(void *virt, unsigned long size);
+unsigned long hyp_early_alloc_nr_pages(void);
+void *hyp_early_alloc_page(void *arg);
+void *hyp_early_alloc_contig(unsigned int nr_pages);
+
+extern struct kvm_pgtable_mm_ops hyp_early_alloc_mm_ops;
+
+#endif /* __KVM_HYP_EARLY_ALLOC_H */
diff --git a/arch/arm64/kvm/hyp/include/nvhe/memory.h b/arch/arm64/kvm/hyp/include/nvhe/memory.h
new file mode 100644
index 000000000000..64c44c142c95
--- /dev/null
+++ b/arch/arm64/kvm/hyp/include/nvhe/memory.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __KVM_HYP_MEMORY_H
+#define __KVM_HYP_MEMORY_H
+
+#include <asm/page.h>
+
+#include <linux/types.h>
+
+extern s64 hyp_physvirt_offset;
+
+#define __hyp_pa(virt)	((phys_addr_t)(virt) + hyp_physvirt_offset)
+#define __hyp_va(virt)	((void *)((phys_addr_t)(virt) - hyp_physvirt_offset))
+
+static inline void *hyp_phys_to_virt(phys_addr_t phys)
+{
+	return __hyp_va(phys);
+}
+
+static inline phys_addr_t hyp_virt_to_phys(void *addr)
+{
+	return __hyp_pa(addr);
+}
+
+#endif /* __KVM_HYP_MEMORY_H */
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index 590fdefb42dd..1fc0684a7678 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -10,7 +10,7 @@ lib-objs := clear_page.o copy_page.o memcpy.o memset.o
 lib-objs := $(addprefix ../../../lib/, $(lib-objs))
 
 obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o \
-	 hyp-main.o hyp-smp.o psci-relay.o
+	 hyp-main.o hyp-smp.o psci-relay.o early_alloc.o
 obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
 	 ../fpsimd.o ../hyp-entry.o ../exception.o
 obj-y += $(lib-objs)
diff --git a/arch/arm64/kvm/hyp/nvhe/early_alloc.c b/arch/arm64/kvm/hyp/nvhe/early_alloc.c
new file mode 100644
index 000000000000..de4c45662970
--- /dev/null
+++ b/arch/arm64/kvm/hyp/nvhe/early_alloc.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Google LLC
+ * Author: Quentin Perret <qperret@google.com>
+ */
+
+#include <asm/kvm_pgtable.h>
+
+#include <nvhe/memory.h>
+
+struct kvm_pgtable_mm_ops hyp_early_alloc_mm_ops;
+s64 __ro_after_init hyp_physvirt_offset;
+
+static unsigned long base;
+static unsigned long end;
+static unsigned long cur;
+
+unsigned long hyp_early_alloc_nr_pages(void)
+{
+	return (cur - base) >> PAGE_SHIFT;
+}
+
+extern void clear_page(void *to);
+
+void *hyp_early_alloc_contig(unsigned int nr_pages)
+{
+	unsigned long ret = cur, i, p;
+
+	if (!nr_pages)
+		return NULL;
+
+	cur += nr_pages << PAGE_SHIFT;
+	if (cur > end) {
+		cur = ret;
+		return NULL;
+	}
+
+	for (i = 0; i < nr_pages; i++) {
+		p = ret + (i << PAGE_SHIFT);
+		clear_page((void *)(p));
+	}
+
+	return (void *)ret;
+}
+
+void *hyp_early_alloc_page(void *arg)
+{
+	return hyp_early_alloc_contig(1);
+}
+
+void hyp_early_alloc_init(unsigned long virt, unsigned long size)
+{
+	base = virt;
+	end = virt + size;
+	cur = virt;
+
+	hyp_early_alloc_mm_ops.zalloc_page = hyp_early_alloc_page;
+	hyp_early_alloc_mm_ops.phys_to_virt = hyp_phys_to_virt;
+	hyp_early_alloc_mm_ops.virt_to_phys = hyp_virt_to_phys;
+}
diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
index 313ef42f0eab..dbe57ae84a0c 100644
--- a/arch/arm64/kvm/hyp/nvhe/psci-relay.c
+++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
@@ -14,6 +14,8 @@
 #include <kvm/arm_psci.h>
 #include <uapi/linux/psci.h>
 
+#include <nvhe/memory.h>
+
 #define INVALID_CPU_ID UINT_MAX
 
 extern char __kvm_hyp_cpu_entry[];
@@ -21,9 +23,6 @@ extern char __kvm_hyp_cpu_entry[];
 /* Config options set by the host. */
 u32 __ro_after_init kvm_host_psci_version = PSCI_VERSION(0, 0);
 u32 __ro_after_init kvm_host_psci_function_id[PSCI_FN_MAX];
-s64 __ro_after_init hyp_physvirt_offset;
-
-#define __hyp_pa(x) ((phys_addr_t)((x)) + hyp_physvirt_offset)
 
 struct kvm_host_psci_state {
 	atomic_t pending_on;
-- 
2.29.2.299.gdc1121823c-goog

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  parent reply	other threads:[~2020-11-17 18:16 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-17 18:15 [RFC PATCH 00/27] KVM/arm64: A stage 2 for the host Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 01/27] arm64: lib: Annotate {clear, copy}_page() as position-independent Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 02/27] KVM: arm64: Link position-independent string routines into .hyp.text Quentin Perret
2020-11-23 12:34   ` David Brazdil
2020-11-23 14:06     ` Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 03/27] KVM: arm64: Add standalone ticket spinlock implementation for use at hyp Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 04/27] KVM: arm64: Initialize kvm_nvhe_init_params early Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 05/27] KVM: arm64: Avoid free_page() in page-table allocator Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 06/27] KVM: arm64: Factor memory allocation out of pgtable.c Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 07/27] KVM: arm64: Introduce a BSS section for use at Hyp Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 08/27] KVM: arm64: Make kvm_call_hyp() a function call " Quentin Perret
2020-11-23 12:51   ` David Brazdil
2020-11-17 18:15 ` [RFC PATCH 09/27] KVM: arm64: Allow using kvm_nvhe_sym() in hyp code Quentin Perret
2020-11-23 12:57   ` David Brazdil
2020-11-23 14:02     ` Quentin Perret
2020-11-23 14:54       ` David Brazdil
2020-11-17 18:15 ` Quentin Perret [this message]
2020-11-17 18:15 ` [RFC PATCH 11/27] KVM: arm64: Stub CONFIG_DEBUG_LIST at Hyp Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 12/27] KVM: arm64: Introduce a Hyp buddy page allocator Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 13/27] KVM: arm64: Enable access to sanitized CPU features at EL2 Quentin Perret
2020-11-23 10:55   ` Fuad Tabba
2020-11-23 13:51     ` Quentin Perret
2020-11-23 13:22   ` David Brazdil
2020-11-23 14:39     ` Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 14/27] KVM: arm64: Factor out vector address calculation Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 15/27] of/fdt: Introduce early_init_dt_add_memory_hyp() Quentin Perret
2020-11-17 19:44   ` Rob Herring
2020-11-18  9:25     ` Quentin Perret
2020-11-18 14:31       ` Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 16/27] KVM: arm64: Prepare Hyp memory protection Quentin Perret
2020-12-03 12:57   ` Fuad Tabba
2020-12-04 18:01     ` Quentin Perret
2020-12-07 10:20       ` Will Deacon
2020-12-07 11:05         ` Mark Rutland
2020-12-07 11:10           ` Will Deacon
2020-12-07 11:14           ` Fuad Tabba
2020-12-07 11:16       ` Fuad Tabba
2020-12-07 11:58         ` Quentin Perret
2020-12-07 13:54           ` Marc Zyngier
2020-12-07 14:17             ` Quentin Perret
2020-12-07 13:40   ` Will Deacon
2020-12-07 14:11     ` Quentin Perret
2020-12-08  9:40       ` Will Deacon
2020-11-17 18:15 ` [RFC PATCH 17/27] KVM: arm64: Elevate Hyp mappings creation at EL2 Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 18/27] KVM: arm64: Use kvm_arch for stage 2 pgtable Quentin Perret
2020-11-17 18:15 ` [RFC PATCH 19/27] KVM: arm64: Use kvm_arch in kvm_s2_mmu Quentin Perret
2020-11-17 18:16 ` [RFC PATCH 20/27] KVM: arm64: Set host stage 2 using kvm_nvhe_init_params Quentin Perret
2020-11-17 18:16 ` [RFC PATCH 21/27] KVM: arm64: Refactor kvm_arm_setup_stage2() Quentin Perret
2020-11-17 18:16 ` [RFC PATCH 22/27] KVM: arm64: Refactor __load_guest_stage2() Quentin Perret
2020-11-17 18:16 ` [RFC PATCH 23/27] KVM: arm64: Refactor __populate_fault_info() Quentin Perret
2020-11-17 18:16 ` [RFC PATCH 24/27] KVM: arm64: Make memcache anonymous in pgtable allocator Quentin Perret
2020-11-17 18:16 ` [RFC PATCH 25/27] KVM: arm64: Reserve memory for host stage 2 Quentin Perret
2020-11-17 18:16 ` [RFC PATCH 26/27] KVM: arm64: Sort the memblock regions list Quentin Perret
2020-11-17 18:16 ` [RFC PATCH 27/27] KVM: arm64: Wrap the host with a stage 2 Quentin Perret

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