From: Quentin Perret <qperret@google.com>
To: Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Fuad Tabba <tabba@google.com>,
David Brazdil <dbrazdil@google.com>
Cc: linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
kernel-team@android.com
Subject: [PATCH 05/16] KVM: arm64: Accept page ranges in pkvm share hypercall
Date: Wed, 13 Oct 2021 16:58:20 +0100 [thread overview]
Message-ID: <20211013155831.943476-6-qperret@google.com> (raw)
In-Reply-To: <20211013155831.943476-1-qperret@google.com>
The recently reworked do_share() infrastructure for the nVHE protected
mode allows to transition the state of a range of pages 'atomically'.
This is preferable over single-page sharing when e.g. mapping guest
vCPUs in the hypervisor stage-1 as the permission checks and page-table
modifications for the entire range are done in a single critical
section. This means there is no need for the host the handle e.g. only
half of a vCPU being successfully shared with the hypervisor.
So, make use of that feature in the __pkvm_host_share_hyp() hypercall by
allowing to specify a pfn range.
Signed-off-by: Quentin Perret <qperret@google.com>
---
arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 2 +-
arch/arm64/kvm/hyp/nvhe/hyp-main.c | 3 ++-
arch/arm64/kvm/hyp/nvhe/mem_protect.c | 4 +--
arch/arm64/kvm/mmu.c | 25 +++++++------------
4 files changed, 14 insertions(+), 20 deletions(-)
diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
index 56445586c755..9c02abe92e0a 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
@@ -54,7 +54,7 @@ extern struct host_kvm host_kvm;
extern const u8 pkvm_hyp_id;
int __pkvm_prot_finalize(void);
-int __pkvm_host_share_hyp(u64 pfn);
+int __pkvm_host_share_hyp(u64 pfn, u64 nr_pages);
bool addr_is_memory(phys_addr_t phys);
int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot);
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 2da6aa8da868..f78bec2b9dd4 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -143,8 +143,9 @@ static void handle___pkvm_cpu_set_vector(struct kvm_cpu_context *host_ctxt)
static void handle___pkvm_host_share_hyp(struct kvm_cpu_context *host_ctxt)
{
DECLARE_REG(u64, pfn, host_ctxt, 1);
+ DECLARE_REG(u64, nr_pages, host_ctxt, 2);
- cpu_reg(host_ctxt, 1) = __pkvm_host_share_hyp(pfn);
+ cpu_reg(host_ctxt, 1) = __pkvm_host_share_hyp(pfn, nr_pages);
}
static void handle___pkvm_create_private_mapping(struct kvm_cpu_context *host_ctxt)
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 6983b83f799f..909e60f71b06 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -671,14 +671,14 @@ static int do_share(struct pkvm_mem_share *share)
return ret;
}
-int __pkvm_host_share_hyp(u64 pfn)
+int __pkvm_host_share_hyp(u64 pfn, u64 nr_pages)
{
int ret;
u64 host_addr = hyp_pfn_to_phys(pfn);
u64 hyp_addr = (u64)__hyp_va(host_addr);
struct pkvm_mem_share share = {
.tx = {
- .nr_pages = 1,
+ .nr_pages = nr_pages,
.initiator = {
.id = PKVM_ID_HOST,
.addr = host_addr,
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index f80673e863ac..bc9865a8c988 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -281,30 +281,23 @@ static phys_addr_t kvm_kaddr_to_phys(void *kaddr)
}
}
-static int pkvm_share_hyp(phys_addr_t start, phys_addr_t end)
-{
- phys_addr_t addr;
- int ret;
-
- for (addr = ALIGN_DOWN(start, PAGE_SIZE); addr < end; addr += PAGE_SIZE) {
- ret = kvm_call_hyp_nvhe(__pkvm_host_share_hyp,
- __phys_to_pfn(addr));
- if (ret)
- return ret;
- }
-
- return 0;
-}
-
int kvm_share_hyp(void *from, void *to)
{
+ phys_addr_t start, end;
+ u64 nr_pages;
+
if (is_kernel_in_hyp_mode())
return 0;
if (kvm_host_owns_hyp_mappings())
return create_hyp_mappings(from, to, PAGE_HYP);
- return pkvm_share_hyp(kvm_kaddr_to_phys(from), kvm_kaddr_to_phys(to));
+ start = ALIGN_DOWN(kvm_kaddr_to_phys(from), PAGE_SIZE);
+ end = PAGE_ALIGN(kvm_kaddr_to_phys(to));
+ nr_pages = (end - start) >> PAGE_SHIFT;
+
+ return kvm_call_hyp_nvhe(__pkvm_host_share_hyp, __phys_to_pfn(start),
+ nr_pages);
}
/**
--
2.33.0.882.g93a45727a2-goog
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next prev parent reply other threads:[~2021-10-13 16:02 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-13 15:58 [PATCH 00/16] KVM: arm64: Implement unshare hypercall for pkvm Quentin Perret
2021-10-13 15:58 ` [PATCH 01/16] KVM: arm64: Introduce do_share() helper for memory sharing between components Quentin Perret
2021-10-15 15:11 ` Andrew Walbran
2021-10-19 10:37 ` Quentin Perret
2021-10-13 15:58 ` [PATCH 02/16] KVM: arm64: Implement __pkvm_host_share_hyp() using do_share() Quentin Perret
2021-10-13 15:58 ` [PATCH 03/16] KVM: arm64: Avoid remapping the SVE state in the hyp stage-1 Quentin Perret
2021-10-16 11:04 ` Marc Zyngier
2021-10-18 10:36 ` Quentin Perret
2021-10-13 15:58 ` [PATCH 04/16] KVM: arm64: Introduce kvm_share_hyp() Quentin Perret
2021-10-17 10:41 ` Marc Zyngier
2021-10-18 10:51 ` Quentin Perret
2021-10-13 15:58 ` Quentin Perret [this message]
2021-10-13 15:58 ` [PATCH 06/16] KVM: arm64: Provide {get,put}_page() stubs for early hyp allocator Quentin Perret
2021-10-13 15:58 ` [PATCH 07/16] KVM: arm64: Refcount hyp stage-1 pgtable pages Quentin Perret
2021-10-13 15:58 ` [PATCH 08/16] KVM: arm64: Fixup hyp stage-1 refcount Quentin Perret
2021-10-13 15:58 ` [PATCH 09/16] KVM: arm64: Hook up ->page_count() for hypervisor stage-1 page-table Quentin Perret
2021-10-13 15:58 ` [PATCH 10/16] KVM: arm64: Implement kvm_pgtable_hyp_unmap() at EL2 Quentin Perret
2021-10-13 15:58 ` [PATCH 11/16] KVM: arm64: Back hyp_vmemmap for all of memory Quentin Perret
2021-10-13 15:58 ` [PATCH 12/16] KVM: arm64: Move hyp refcount helpers to header files Quentin Perret
2021-10-13 15:58 ` [PATCH 13/16] KVM: arm64: Move double-sharing logic into hyp-specific function Quentin Perret
2021-10-13 15:58 ` [PATCH 14/16] KVM: arm64: Refcount shared pages at EL2 Quentin Perret
2021-10-13 15:58 ` [PATCH 15/16] KVM: arm64: pkvm: Introduce an unshare hypercall Quentin Perret
2021-10-13 15:58 ` [PATCH 16/16] KVM: arm64: pkvm: Unshare guest structs during teardown Quentin Perret
2021-10-16 12:25 ` Marc Zyngier
2021-10-18 10:32 ` Quentin Perret
2021-10-18 14:03 ` Quentin Perret
2021-10-18 17:12 ` Marc Zyngier
2021-10-19 9:40 ` Quentin Perret
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