On Mon, Feb 20, 2023 at 12:37:53PM -0600,
Michael Roth <michael.roth@xxxxxxx> wrote:
> This callback will do any platform-specific handling needed for
> converting pages between shared/private.
>
> Signed-off-by: Michael Roth <michael.roth@xxxxxxx>
> ---
> arch/x86/include/asm/kvm-x86-ops.h | 1 +
> arch/x86/include/asm/kvm_host.h | 2 ++
> arch/x86/kvm/mmu/mmu.c | 13 +++++++++++++
> include/linux/kvm_host.h | 4 ++++
> virt/kvm/kvm_main.c | 29 +++++++++++++++++++++++++++++
> 5 files changed, 49 insertions(+)
>
> diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
> index 72183da010b8..a8aaf532c2ab 100644
> --- a/arch/x86/include/asm/kvm-x86-ops.h
> +++ b/arch/x86/include/asm/kvm-x86-ops.h
> @@ -132,6 +132,7 @@ KVM_X86_OP(complete_emulated_msr)
> KVM_X86_OP(vcpu_deliver_sipi_vector)
> KVM_X86_OP_OPTIONAL_RET0(vcpu_get_apicv_inhibit_reasons);
> KVM_X86_OP_OPTIONAL_RET0(fault_is_private);
> +KVM_X86_OP_OPTIONAL_RET0(update_mem_attr)
>
> #undef KVM_X86_OP
> #undef KVM_X86_OP_OPTIONAL
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index f856d689dda0..2da3fb2d5d1b 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1644,6 +1644,8 @@ struct kvm_x86_ops {
> void (*load_mmu_pgd)(struct kvm_vcpu *vcpu, hpa_t root_hpa,
> int root_level);
> bool (*fault_is_private)(struct kvm *kvm, gpa_t gpa, u64 error_code, bool *private_fault);
> + int (*update_mem_attr)(struct kvm_memory_slot *slot, unsigned int attr,
> + gfn_t start, gfn_t end);
>
> bool (*has_wbinvd_exit)(void);
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index fb3f34b7391c..053bd77bbf52 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -7251,4 +7251,17 @@ void kvm_arch_set_memory_attributes(struct kvm *kvm,
> linfo_update_mixed(gfn, slot, level, mixed);
> }
> }
> +
> +void kvm_arch_post_set_memory_attributes(struct kvm *kvm,
> + struct kvm_memory_slot *slot,
> + unsigned long attrs,
> + gfn_t start, gfn_t end)
> +{
> + int ret;
> +
> + ret = static_call(kvm_x86_update_mem_attr)(slot, attrs, start, end);
> + if (ret)
> + pr_warn_ratelimited("Failed to update GFN range 0x%llx-0x%llx with attributes 0x%lx. Ret: %d\n",
> + start, end, attrs, ret);
> +}
> #endif
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index fdc59479b3e2..d200b8f45583 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -2330,6 +2330,10 @@ void kvm_arch_set_memory_attributes(struct kvm *kvm,
> struct kvm_memory_slot *slot,
> unsigned long attrs,
> gfn_t start, gfn_t end);
> +void kvm_arch_post_set_memory_attributes(struct kvm *kvm,
> + struct kvm_memory_slot *slot,
> + unsigned long attrs,
> + gfn_t start, gfn_t end);
>
> static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn)
> {
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index b68574ff6c30..8ec985f1c57d 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -2561,6 +2561,32 @@ static void kvm_mem_attrs_changed(struct kvm *kvm, unsigned long attrs,
> kvm_flush_remote_tlbs(kvm);
> }
>
> +static void kvm_post_mem_attrs_changed(struct kvm *kvm, unsigned long attrs,
> + gfn_t start_orig, gfn_t end_orig)
> +{
> + struct kvm_memory_slot *slot;
> + struct kvm_memslots *slots;
> + struct kvm_memslot_iter iter;
> + int i;
> +
> + for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) {
> + slots = __kvm_memslots(kvm, i);
> +
> + kvm_for_each_memslot_in_gfn_range(&iter, slots, start_orig, end_orig) {
> + gfn_t start, end;
> +
> + slot = iter.slot;
> + start = max(start_orig, slot->base_gfn);
> + end = min(end_orig, slot->base_gfn + slot->npages);
> +
> + if (start >= end)
> + continue;
> +
> + kvm_arch_post_set_memory_attributes(kvm, slot, attrs, start, end);
> + }
> + }
> +}
> +
> static int kvm_vm_ioctl_set_mem_attributes(struct kvm *kvm,
> struct kvm_memory_attributes *attrs)
> {
> @@ -2602,6 +2628,9 @@ static int kvm_vm_ioctl_set_mem_attributes(struct kvm *kvm,
> kvm_mmu_invalidate_end(kvm);
> KVM_MMU_UNLOCK(kvm);
>
> + if (i > start)
> + kvm_post_mem_attrs_changed(kvm, attrs->attributes, start, i);
> +
Doesn't kvm_arch_set_memory_attributes() work for you? i.e the following patch.
The error check and pr_warn_ratelimited() can be pushed down into the callback.
>From 7c618c1f3c236c382e64680efcbe7d8a672aa870 Mon Sep 17 00:00:00 2001
Message-Id: <7c618c1f3c236c382e64680efcbe7d8a672aa870.1679114841.git.isaku.yamahata@xxxxxxxxx>
In-Reply-To: <428a676face7a06a90e59dca1c32941c9b6ee001.1679114841.git.isaku.yamahata@xxxxxxxxx>
References: <428a676face7a06a90e59dca1c32941c9b6ee001.1679114841.git.isaku.yamahata@xxxxxxxxx>
From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Date: Fri, 17 Mar 2023 12:00:09 -0700
Subject: [PATCH 4/4] KVM: x86: Add 'set_mem_attr' x86 op
This callback will do any platform-specific handling needed for
converting pages between shared/private.
Originally-by: Michael Roth <michael.roth@xxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
arch/x86/include/asm/kvm-x86-ops.h | 1 +
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/mmu/mmu.c | 1 +
3 files changed, 4 insertions(+)
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index dc5f18ac0bd5..956db2ee25a5 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -100,6 +100,7 @@ KVM_X86_OP_OPTIONAL_RET0(set_identity_map_addr)
KVM_X86_OP_OPTIONAL_RET0(get_mt_mask)
KVM_X86_OP(load_mmu_pgd)
KVM_X86_OP(fault_is_private)
+KVM_X86_OP_OPTIONAL(set_mem_attr)
KVM_X86_OP_OPTIONAL(link_private_spt)
KVM_X86_OP_OPTIONAL(free_private_spt)
KVM_X86_OP_OPTIONAL(split_private_spt)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 0382d236fbf4..88e11dd3afde 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1731,6 +1731,8 @@ struct kvm_x86_ops {
void (*load_mmu_pgd)(struct kvm_vcpu *vcpu, hpa_t root_hpa,
int root_level);
bool (*fault_is_private)(struct kvm *kvm, gpa_t gpa, u64 error_code);
+ void (*set_mem_attr)(struct kvm *kvm, struct kvm_memory_slot *slot,
+ unsigned int attr, gfn_t start, gfn_t end);
int (*link_private_spt)(struct kvm *kvm, gfn_t gfn, enum pg_level level,
void *private_spt);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 0ec94c72895c..329333486e64 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -7908,6 +7908,7 @@ void kvm_arch_set_memory_attributes(struct kvm *kvm,
gfn_t start, gfn_t end)
{
kvm_update_lpage_mixed_flag(kvm, slot, true, attrs, start, end);
+ static_call(kvm_x86_set_mem_attr)(kvm, slot, attrs, start, end);
}
void kvm_memory_attributes_create_memslot(struct kvm *kvm,
--
2.25.1
--
Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
