From: Quentin Perret <qperret@google.com>
To: Mate Toth-Pal <mate.toth-pal@arm.com>
Cc: catalin.marinas@arm.com, will@kernel.org, maz@kernel.org,
james.morse@arm.com, julien.thierry.kdev@gmail.com,
suzuki.poulose@arm.com, android-kvm@google.com,
seanjc@google.com, linux-kernel@vger.kernel.org,
robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org,
kernel-team@android.com, kvmarm@lists.cs.columbia.edu,
tabba@google.com, ardb@kernel.org, mark.rutland@arm.com,
dbrazdil@google.com
Subject: Re: [PATCH v5 33/36] KVM: arm64: Wrap the host with a stage 2
Date: Tue, 16 Mar 2021 17:46:42 +0000 [thread overview]
Message-ID: <YFDvAqgimPvpgiwQ@google.com> (raw)
In-Reply-To: <eb70a071-4d4a-885f-36a7-3b20358e5513@arm.com>
On Tuesday 16 Mar 2021 at 16:16:18 (+0100), Mate Toth-Pal wrote:
> On 2021-03-16 15:29, Quentin Perret wrote:
> > On Tuesday 16 Mar 2021 at 12:53:53 (+0000), Quentin Perret wrote:
> > > On Tuesday 16 Mar 2021 at 13:28:42 (+0100), Mate Toth-Pal wrote:
> > > > Changing the value of MT_S2_FWB_NORMAL to 7 would change this behavior, and
> > > > the resulting memory type would be device.
> > >
> > > Sounds like the correct fix here -- see below.
> >
> > Just to clarify this, I meant this should be the configuration for the
> > host stage-2. We'll want to keep the existing behaviour for guests I
> > believe.
>
> I Agree.
OK, so the below seems to boot on my non-FWB-capable hardware and should
fix the issue. Could you by any chance give it a spin?
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index b93a2a3526ab..b2066bd03ca2 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h
@@ -76,10 +76,11 @@ struct kvm_pgtable {
/**
* enum kvm_pgtable_prot - Page-table permissions and attributes.
- * @KVM_PGTABLE_PROT_X: Execute permission.
- * @KVM_PGTABLE_PROT_W: Write permission.
- * @KVM_PGTABLE_PROT_R: Read permission.
- * @KVM_PGTABLE_PROT_DEVICE: Device attributes.
+ * @KVM_PGTABLE_PROT_X: Execute permission.
+ * @KVM_PGTABLE_PROT_W: Write permission.
+ * @KVM_PGTABLE_PROT_R: Read permission.
+ * @KVM_PGTABLE_PROT_DEVICE: Device attributes.
+ * @KVM_PGTABLE_PROT_S2_NOFWB: Don't enforce Normal-WB with FWB.
*/
enum kvm_pgtable_prot {
KVM_PGTABLE_PROT_X = BIT(0),
@@ -87,6 +88,8 @@ enum kvm_pgtable_prot {
KVM_PGTABLE_PROT_R = BIT(2),
KVM_PGTABLE_PROT_DEVICE = BIT(3),
+
+ KVM_PGTABLE_PROT_S2_NOFWB = BIT(4),
};
#define PAGE_HYP (KVM_PGTABLE_PROT_R | KVM_PGTABLE_PROT_W)
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index c759faf7a1ff..e695d2e1839d 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -144,13 +144,16 @@
* Memory types for Stage-2 translation
*/
#define MT_S2_NORMAL 0xf
+#define MT_S2_WEAK MT_S2_NORMAL
#define MT_S2_DEVICE_nGnRE 0x1
/*
* Memory types for Stage-2 translation when ID_AA64MMFR2_EL1.FWB is 0001
- * Stage-2 enforces Normal-WB and Device-nGnRE
+ * Stage-2 enforces Normal-WB and Device-nGnRE by default. The 'weak' mode
+ * honors Stage-1 attributes.
*/
#define MT_S2_FWB_NORMAL 6
+#define MT_S2_FWB_WEAK 7
#define MT_S2_FWB_DEVICE_nGnRE 1
#ifdef CONFIG_ARM64_4K_PAGES
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index dd03252b9574..1ff72babe565 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -214,6 +214,8 @@ static int host_stage2_idmap(u64 addr)
if (is_memory)
prot |= KVM_PGTABLE_PROT_X;
+ else
+ prot |= KVM_PGTABLE_PROT_S2_NOFWB;
hyp_spin_lock(&host_kvm.lock);
ret = kvm_pgtable_stage2_find_range(&host_kvm.pgt, addr, prot, &range);
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 3a971df278bd..bd1b8464a537 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -343,6 +343,9 @@ static int hyp_set_prot_attr(enum kvm_pgtable_prot prot, kvm_pte_t *ptep)
if (!(prot & KVM_PGTABLE_PROT_R))
return -EINVAL;
+ if (prot & KVM_PGTABLE_PROT_S2_NOFWB)
+ return -EINVAL;
+
if (prot & KVM_PGTABLE_PROT_X) {
if (prot & KVM_PGTABLE_PROT_W)
return -EINVAL;
@@ -510,9 +513,18 @@ u64 kvm_get_vtcr(u64 mmfr0, u64 mmfr1, u32 phys_shift)
static int stage2_set_prot_attr(enum kvm_pgtable_prot prot, kvm_pte_t *ptep)
{
bool device = prot & KVM_PGTABLE_PROT_DEVICE;
- kvm_pte_t attr = device ? PAGE_S2_MEMATTR(DEVICE_nGnRE) :
- PAGE_S2_MEMATTR(NORMAL);
+ bool nofwb = prot & KVM_PGTABLE_PROT_S2_NOFWB;
u32 sh = KVM_PTE_LEAF_ATTR_LO_S2_SH_IS;
+ kvm_pte_t attr;
+
+ WARN_ON(nofwb && device);
+
+ if (device)
+ attr = PAGE_S2_MEMATTR(DEVICE_nGnRE);
+ else if (nofwb)
+ attr = PAGE_S2_MEMATTR(WEAK);
+ else
+ attr = PAGE_S2_MEMATTR(NORMAL);
if (!(prot & KVM_PGTABLE_PROT_X))
attr |= KVM_PTE_LEAF_ATTR_HI_S2_XN;
next prev parent reply other threads:[~2021-03-16 17:47 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-15 14:35 [PATCH v5 00/36] KVM: arm64: A stage 2 for the host Quentin Perret
2021-03-15 14:35 ` [PATCH v5 01/36] arm64: lib: Annotate {clear,copy}_page() as position-independent Quentin Perret
2021-03-15 14:35 ` [PATCH v5 02/36] KVM: arm64: Link position-independent string routines into .hyp.text Quentin Perret
2021-03-15 14:35 ` [PATCH v5 03/36] arm64: kvm: Add standalone ticket spinlock implementation for use at hyp Quentin Perret
2021-03-15 14:35 ` [PATCH v5 04/36] KVM: arm64: Initialize kvm_nvhe_init_params early Quentin Perret
2021-03-15 14:35 ` [PATCH v5 05/36] KVM: arm64: Avoid free_page() in page-table allocator Quentin Perret
2021-03-15 14:35 ` [PATCH v5 06/36] KVM: arm64: Factor memory allocation out of pgtable.c Quentin Perret
2021-03-15 14:35 ` [PATCH v5 07/36] KVM: arm64: Introduce a BSS section for use at Hyp Quentin Perret
2021-03-15 14:35 ` [PATCH v5 08/36] KVM: arm64: Make kvm_call_hyp() a function call " Quentin Perret
2021-03-15 14:35 ` [PATCH v5 09/36] KVM: arm64: Allow using kvm_nvhe_sym() in hyp code Quentin Perret
2021-03-15 14:35 ` [PATCH v5 10/36] KVM: arm64: Introduce an early Hyp page allocator Quentin Perret
2021-03-15 14:35 ` [PATCH v5 11/36] KVM: arm64: Stub CONFIG_DEBUG_LIST at Hyp Quentin Perret
2021-03-15 14:35 ` [PATCH v5 12/36] KVM: arm64: Introduce a Hyp buddy page allocator Quentin Perret
2021-03-15 14:35 ` [PATCH v5 13/36] KVM: arm64: Enable access to sanitized CPU features at EL2 Quentin Perret
2021-03-15 14:35 ` [PATCH v5 14/36] KVM: arm64: Provide __flush_dcache_area " Quentin Perret
2021-03-15 16:33 ` Will Deacon
2021-03-15 16:56 ` Quentin Perret
2021-03-15 17:03 ` Will Deacon
2021-03-15 14:35 ` [PATCH v5 15/36] KVM: arm64: Factor out vector address calculation Quentin Perret
2021-03-15 14:35 ` [PATCH v5 16/36] arm64: asm: Provide set_sctlr_el2 macro Quentin Perret
2021-03-15 14:35 ` [PATCH v5 17/36] KVM: arm64: Prepare the creation of s1 mappings at EL2 Quentin Perret
2021-03-15 14:35 ` [PATCH v5 18/36] KVM: arm64: Elevate hypervisor mappings creation " Quentin Perret
2021-03-15 14:35 ` [PATCH v5 19/36] KVM: arm64: Use kvm_arch for stage 2 pgtable Quentin Perret
2021-03-15 14:35 ` [PATCH v5 20/36] KVM: arm64: Use kvm_arch in kvm_s2_mmu Quentin Perret
2021-03-15 14:35 ` [PATCH v5 21/36] KVM: arm64: Set host stage 2 using kvm_nvhe_init_params Quentin Perret
2021-03-15 14:35 ` [PATCH v5 22/36] KVM: arm64: Refactor kvm_arm_setup_stage2() Quentin Perret
2021-03-15 14:35 ` [PATCH v5 23/36] KVM: arm64: Refactor __load_guest_stage2() Quentin Perret
2021-03-15 14:35 ` [PATCH v5 24/36] KVM: arm64: Refactor __populate_fault_info() Quentin Perret
2021-03-15 14:35 ` [PATCH v5 25/36] KVM: arm64: Make memcache anonymous in pgtable allocator Quentin Perret
2021-03-15 14:35 ` [PATCH v5 26/36] KVM: arm64: Reserve memory for host stage 2 Quentin Perret
2021-03-15 14:35 ` [PATCH v5 27/36] KVM: arm64: Sort the hypervisor memblocks Quentin Perret
2021-03-15 14:35 ` [PATCH v5 28/36] KVM: arm64: Always zero invalid PTEs Quentin Perret
2021-03-15 14:35 ` [PATCH v5 29/36] KVM: arm64: Use page-table to track page ownership Quentin Perret
2021-03-15 16:36 ` Will Deacon
2021-03-15 16:53 ` Quentin Perret
2021-03-15 17:01 ` Will Deacon
2021-03-15 14:35 ` [PATCH v5 30/36] KVM: arm64: Refactor the *_map_set_prot_attr() helpers Quentin Perret
2021-03-15 14:35 ` [PATCH v5 31/36] KVM: arm64: Add kvm_pgtable_stage2_find_range() Quentin Perret
2021-03-15 16:31 ` Will Deacon
2021-03-15 14:35 ` [PATCH v5 32/36] KVM: arm64: Provide sanitized mmfr* registers at EL2 Quentin Perret
2021-03-15 16:31 ` Will Deacon
2021-03-15 14:35 ` [PATCH v5 33/36] KVM: arm64: Wrap the host with a stage 2 Quentin Perret
2021-03-16 12:28 ` Mate Toth-Pal
2021-03-16 12:53 ` Quentin Perret
2021-03-16 14:29 ` Quentin Perret
2021-03-16 15:16 ` Mate Toth-Pal
2021-03-16 17:46 ` Quentin Perret [this message]
2021-03-17 8:41 ` Mate Toth-Pal
2021-03-17 9:02 ` Quentin Perret
2021-03-17 14:57 ` Mate Toth-Pal
2021-03-17 14:17 ` [PATCH 0/2] Fixes for FWB Quentin Perret
2021-03-17 14:17 ` [PATCH 1/2] KVM: arm64: Introduce KVM_PGTABLE_S2_NOFWB Stage-2 flag Quentin Perret
2021-03-17 14:41 ` Marc Zyngier
2021-03-17 14:47 ` Quentin Perret
2021-03-17 14:42 ` Will Deacon
2021-03-17 14:51 ` Quentin Perret
2021-03-17 14:17 ` [PATCH 2/2] KVM: arm64: Disable FWB in host stage-2 Quentin Perret
2021-03-15 14:35 ` [PATCH v5 34/36] KVM: arm64: Page-align the .hyp sections Quentin Perret
2021-03-15 14:35 ` [PATCH v5 35/36] KVM: arm64: Disable PMU support in protected mode Quentin Perret
2021-03-15 14:35 ` [PATCH v5 36/36] KVM: arm64: Protect the .hyp sections from the host Quentin Perret
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