From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8A9FA471D0B for ; Thu, 24 Sep 2026 10:38:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790246285; cv=none; b=DjGAoLiKrhU0Y3/Dw/rxOHZI+tO3IxAMoUga4emr9rxY+yW8Uvy0W82U0hFS8QBdatIkoihgU/l/FnbEo7Crmvt5Idal8ExrleAqEyCdUnXVaGpU8k+N6D5s27m6tvKsbgs1KeGBo0C6Kr6xNsAPT0vk+6IQHj+QSkTfX+iTryY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790246285; c=relaxed/simple; bh=A8xsQJ2linduh8LyiNqxYa3X+Ud+PNJ2iO8AypsdtIs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=FWONU6sh3IJhzEyGCS3QfCpgUEuJ2LazQIwpaq0wA1QHflf1oNy6EA13sURUsfJM3w7uoUK3hKuNHicRn9CAe2OLbi2+fUhHuAsrd2R0hbALGLZZEvPggo8HCD7+NsJRHO28kxH4y5UxaSnBvjq688Yc2y95RPqusy+J5tbZAbA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=iu4JdmcY; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="iu4JdmcY" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1790246281; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uAVbcKNtAzIm2if8Vp//CW0uy9ovqdlJEmpzowvI5xg=; b=iu4JdmcYQUyp/bJojiax9tbADBUjoGGy5DKFQ0KrefDjfIhh6zqtWDEvRTDHNXf1Jtv3Yj z5ttsXuu/R7m5/tseEjv71CutJXRAsf+LulX8lX0S1tRBcU3VxEz4aa7D48y13ZYVAUJGx wnqSA+jj/lECMn1LfDOjmBkLB7QjQHo= Received: from mail-pj1-f71.google.com (mail-pj1-f71.google.com [209.85.216.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-253-IBcd7CNhPx-sliWWerZKFg-1; Thu, 24 Sep 2026 06:37:58 -0400 X-MC-Unique: IBcd7CNhPx-sliWWerZKFg-1 X-Mimecast-MFC-AGG-ID: IBcd7CNhPx-sliWWerZKFg_1790246277 Received: by mail-pj1-f71.google.com with SMTP id 98e67ed59e1d1-3965ba1ba3eso1620845a91.2 for ; Thu, 24 Sep 2026 03:37:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790246277; x=1790851077; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=uAVbcKNtAzIm2if8Vp//CW0uy9ovqdlJEmpzowvI5xg=; b=g5HFKdZnt4G15OehPP4AVxsvz0gWZ+S/RGB2LC3iXh8vEZBqJcx/df/FsMLcOZ9Z0w z6ygtOzR13J/9selZT8okPcHymSPxsb0jYhS43CgeUkq9AK+9eFdNhogTKq0psq8wW60 TP2T5ezsk7HzoGr6MyGTVZuAmx2cpMSpmk1JFVWkV2NHEnSdA83Zbwj214uIzh8uO1Xq BYaNPW3PHp7qkPvGaWQ+V8np8lObyQFT0bMHHUfyLMkh/B02AP38fZ12R9XtUzQ7ttCk wgcDG3W/ikuGU13Bd+AlRprIrlffPXxALsZUIpgGMGBJk0lUq93y08wL8/gMCWjC47V/ 47/g== X-Forwarded-Encrypted: i=1; AKwUvBzCyL1mikR6WHM0r221Nm/qWFOdC3E+U1T725BZfTl6u4QQ4NjHAStSqwd9qX4FdbCwqy46v1ET1o/L@lists.linux.dev X-Gm-Message-State: AFuF++mfijVdCBNy5I/eFv47v8e1Wk1dy8GcmLGHj/T4i5B45ZePkOxw uWPBOEPcMTFr61Jm5tVAuy9EsNd/jnQ66sKH+jWIlDJDu0xst80sNiPL2VYOPP5bVg+/n3XV2YS NhaurnJUBnGSKWyv8Bu6iPVQNOtTcst0gYNZm46b6sKpxzmszxAY+ayVIkH4VpyM= X-Gm-Gg: AYBFou2u0xsqI50QLPcEzNDnKhq1grXbk/Oo6+glEBS2sUD4osgsEEbf7cT+rgj+SCe gOgtDjopw2Gsfpvx83+w0tg7ENPzCsfwdEzAQB1oeBFLnY48OjHh4Rhu+HNN4EvYvRpUa0fte3P YX4eQ/Lpay9axBzxbnP38Z+r2zqktcQDBNBBLu5EjAI6o69gTsRghbEIG3PqLOugr2HaRRysz2k EIifbGjoPUVj8I1Ix9gZhpnNOVNNqnUm1rmHHHk1OSk1lahhYfuI1ejnkreSxwIrMlhOT/O/xFo gxfXEB3h6bPnyYwfqy25o645IMzpQZmZNjZY6CEHLmsn0K6XWdLP+hGmZO7dTIbt14hMhoeCAqW /RuIH2x49MvDm7/y1CPPbLikXvOz76n/ESkLCOWQjDw== X-Received: by 2002:a17:90b:4c0d:b0:36d:9e0b:3801 with SMTP id 98e67ed59e1d1-3a0985baa7dmr1701218a91.8.1790246276937; Thu, 24 Sep 2026 03:37:56 -0700 (PDT) X-Received: by 2002:a17:90b:4c0d:b0:36d:9e0b:3801 with SMTP id 98e67ed59e1d1-3a0985baa7dmr1701179a91.8.1790246276182; Thu, 24 Sep 2026 03:37:56 -0700 (PDT) Received: from [192.168.68.52] (n175-34-8-244.mrk21.qld.optusnet.com.au. [175.34.8.244]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3a097663fd0sm4220632a91.9.2026.09.24.03.37.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 24 Sep 2026 03:37:55 -0700 (PDT) Message-ID: Date: Thu, 24 Sep 2026 20:37:46 +1000 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v19 05/20] KVM: arm64: Track the type of VM in kvm_arch To: Suzuki K Poulose , kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: maz@kernel.org, will@kernel.org, catalin.marinas@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, steven.price@arm.com, aneesh.kumar@kernel.org, oupton@kernel.org, joey.gouly@arm.com, tabba@google.com, yuzenghui@huawei.com, linux-coco@lists.linux.dev, gankulkarni@os.amperecomputing.com, sdonthineni@nvidia.com, alpergun@google.com, fj0570is@fujitsu.com, WeiLin.Chang@arm.com, lpieralisi@kernel.org, enju.kohei@fujitsu.com References: <20260920212845.707-1-suzuki.poulose@arm.com> <20260920212845.707-6-suzuki.poulose@arm.com> <69ff265b-a110-46c5-a061-a875b2f86c03@redhat.com> <672c4905-09c9-4e40-97ea-c87a987bda19@arm.com> <0ddf1529-a198-413d-bffb-1dbc7b6ee25f@redhat.com> <700e9eaf-b3e8-4129-9471-25de73f008b3@arm.com> From: Gavin Shan In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: jzcYyEuv1trWSjLErce99GnNKlfk-dXocqW41eQBovo_1790246277 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 9/24/26 6:48 PM, Suzuki K Poulose wrote: > On 24/09/2026 02:11, Gavin Shan wrote: >> On 9/24/26 7:37 AM, Suzuki K Poulose wrote: >>> On 23/09/2026 17:27, Suzuki K Poulose wrote: >>>> On 23/09/2026 14:23, Gavin Shan wrote: >>>>> On 9/23/26 8:24 PM, Suzuki K Poulose wrote: >>>>>> On 23/09/2026 07:19, Gavin Shan wrote: >>>>>>> On 9/23/26 4:05 PM, Gavin Shan wrote: >>>>>>>> On 9/21/26 7:28 AM, Suzuki K Poulose wrote: >>>>>>>>> KVM arm64 has different types of VMs with all the different modes in which >>>>>>>>> the hypervisor code can be run. e.g., VHE, nVHE, pKVM etc. Then there is >>>>>>>>> protected VM and normal VMs with pKVM. We might soon add other types, >>>>>>>>> e.g., Arm CCA Realm. So in an effort to make the handling of these >>>>>>>>> different types of VMs a bit more friendly to the eyes, add a VM flavor to >>>>>>>>> the kvm_arch and we could then add handlers for different operations based >>>>>>>>> on the VM type. >>>>>>>>> >>>>>>>>> Keep the flavor initialisation at the beginning to allow for the detection >>>>>>>>> early enough and fail out on any unsupported requests. >>>>>>>>> >>>>>>>>> With that, add wrappers for checking the "type" of a VM and replace the >>>>>>>>> existing users with the new wrappers. >>>>>>>>> >>>>>>>>> Given we already have the construct of "kvm_vm_is_protected" in the core >>>>>>>>> KVM code, use that for all confidential compute guests including Realms >>>>>>>>> that we are about to add. >>>>>>>>> >>>>>>>>> Adds __VM_PROTECTED marker vm flavor to generalize kvm_vm_is_protected() >>>>>>>>> to predicate all confidential guests running on KVM. In later patches, we >>>>>>>>> would add Realm VMs, which would also be classified as protected. >>>>>>>>> >>>>>>>>> Add explicit helper to detect if a given VM is a "protected" VM under pKVM. >>>>>>>>> Change the existing users that precisely want to check the VM type. These >>>>>>>>> include : >>>>>>>>>    - kvm_arch_prepare_memory_region - For preventing memslot changes after >>>>>>>>>      pVM creation. >>>>>>>>> >>>>>>>>> All the others are retained as a wider check for confidential guest VMs. >>>>>>>>> These are: >>>>>>>>>   - kvm_vm_ioctl_set_counter_offset - For disallowing timer offset >>>>>>>>>     configuration >>>>>>>>>   - io_mem_abort for dabt handling without valid syndrome information >>>>>>>>> >>>>>>>>> Both of which are true for Realms too. >>>>>>>>> >>>>>>>>> Realms support is restricted to VHE host and thus "kvm_vm_is_protected()" >>>>>>>>> checks in the pkvm hyp specific code doesn't need to change, as the only >>>>>>>>> protected guests it deals with is "protected pKVM" guests. To tighten this >>>>>>>>> init_pkvm_hyp_vm() restricts the hyp copy of the vm_flavor to the ones it >>>>>>>>> supports. >>>>>>>>> >>>>>>>>> Suggested-by: Marc Zyngier >>>>>>>>> Signed-off-by: Suzuki K Poulose >>>>>>>>> --- >>>>>>>>> Changes since v18: >>>>>>>>>   - Merge the __VM_PROTECTED marker and the widening of kvm_vm_is_protected() >>>>>>>>>     to this patch. >>>>>>>>>   - Merge the use of kvm_vm_is_unprotected_pkvm() for ! kvm_vm_is_protected() >>>>>>>>>     given the scope changes here. >>>>>>>>>   - Drop Fuad's review tag, as this patch has multiple merges >>>>>>>>>   - Restrict the VM flavors to the supported types in init_pkvm_hyp_vm(). >>>>>>>>>   - Drop kvm_vm_hyp_is_pkvm() and revert to is_protected_kvm_enabled() >>>>>>>>>   - Use is_protected_kvm_enabled() to make the pKVM guest flavor checks. >>>>>>>>>   - s/PKVM/pKVM for commit descriptions too >>>>>>>>> >>>>>>>>> Changes since v17: >>>>>>>>>   * s/PKVM/pKVM for the comments >>>>>>>>>   * Drop type argument for pkvm_init_host_vm and also drop protected variable. >>>>>>>>>   * Add helpers for checking if the VM is running on pKVM (kvm_vm_hyp_is_pkvm()) >>>>>>>>>   * Use kvm_vm_hyp_is_pkvm() to replace is_protected_kvm_enabled() with valid >>>>>>>>>     kvm instance >>>>>>>>> --- >>>>>>>>>   arch/arm64/include/asm/kvm_host.h | 22 +++++++++++++++++++--- >>>>>>>>>   arch/arm64/include/asm/kvm_pkvm.h |  4 ++-- >>>>>>>>>   arch/arm64/kvm/arm.c              | 31 +++++++++++++++++++++++ ++ +----- >>>>>>>>>   arch/arm64/kvm/handle_exit.c      |  2 +- >>>>>>>>>   arch/arm64/kvm/hyp/nvhe/pkvm.c    |  6 +++++- >>>>>>>>>   arch/arm64/kvm/mmu.c              |  2 +- >>>>>>>>>   arch/arm64/kvm/pkvm.c             |  6 ++---- >>>>>>>>>   7 files changed, 56 insertions(+), 17 deletions(-) >>>>>>>>> >>>>>>>> >>>>>>>> This causes broken nVHE mode. I applied PATCH[01-05] to v7.3.rc4 whose head commit >>>>>>>> is f0100363d8c3, and kselftests/kvm/guest_print causes host crash (as below). I don't >>>>>>>> see the crash if only PATCH[01-04] are applied. >>>>>>>> >>>>>>>> host$ cat /proc/cmdline | grep kvm-arm\.mode >>>>>>>> BOOT_IMAGE=(hd0,gpt2)/vmlinuz-7.3.0-rc4-gavin+ root=/dev/mapper/ rhel_nvidia--grace--hopper--01-root ro crashkernel=2G-4G:406M,4G-64G:470M,64G-:726M rd.lvm.lv=rhel_nvidia- grace-hopper-01/root rd.lvm.lv=rhel_nvidia-grace-hopper-01/swap video=simplefb:off kvm-arm.mode=nvhe >>>>>>>> >>>>>>>> host$ cd linux/tools/testing/selftests/kvm >>>>>>>> host$ ./guest_print_test >>>>>>>> Random seed: 0x193a0ed3 >>>>>>>> [  192.754328] kvm [6674]: nVHE hyp panic at: [] __kvm_nvhe___timer_enable_traps+0x4/0x160! >>>>>>>> [  192.754338] kvm [6674]: nVHE call trace: >>>>>>>> [  192.754339] kvm [6674]:  [] __kvm_nvhe_hyp_panic+0xb4/0xe0 >>>>>>>> [  192.754342] kvm [6674]:  [] __kvm_nvhe___kvm_vcpu_run+0x164/0x440 >>>>>>>> [  192.754344] kvm [6674]:  [] __kvm_nvhe_handle___kvm_vcpu_run+0x40/0x1f0 >>>>>>>> [  192.754346] kvm [6674]:  [] __kvm_nvhe_handle_trap+0x158/0x280 >>>>>>>> [  192.754347] kvm [6674]:  [] __kvm_nvhe___skip_pauth_save+0x4/0x4 >>>>>>>> [  192.754348] kvm [6674]: ---[ end nVHE call trace ]--- >>>>>>>> [  192.754350] Code: d2818002 17fffff7 d503201f f9400001 (b94a6821) >>>>>>>> [  192.754350] kvm [6674]: Hyp Offset: 0xfffeb0d7fe2e0000 >>>>>>>> [  192.754351] Kernel panic - not syncing: HYP panic: >>>>>>>> [  192.754351] PS:834003c9 PC:0000cf2882efa044 ESR:0000000096000004 >>>>>>>> [  192.754351] FAR:ffff00009b286a68 HPFAR:8000000000000000 PAR:1d00ec7edbadc8de >>>>>>>> [  192.754351] VCPU:0000cf011848a350 >>>>>>>> [  192.845154] CPU: 12 UID: 0 PID: 6674 Comm: guest_print_tes Kdump: loaded Not tainted 7.3.0-rc4-gavin+ #7 PREEMPT(full) >>>>>>>> [  192.856182] Hardware name:  GH200 P5042, BIOS 02.04.01 20250422 >>>>>>>> [  192.862231] Call trace: >>>>>>>> [  192.864725]  show_stack+0x20/0x38 (C) >>>>>>>> [  192.868471]  dump_stack_lvl+0x88/0xb8 >>>>>>>> [  192.872215]  dump_stack+0x18/0x30 >>>>>>>> [  192.875598]  vpanic+0x280/0x498 >>>>>>>> [  192.878806]  panic+0x68/0x70 >>>>>>>> [  192.881745]  nvhe_hyp_panic_handler+0x184/0x190 >>>>>>>> [  192.886372]  kvm_arm_vcpu_enter_exit+0x24/0x100 >>>>>>>> [  192.891003]  kvm_arch_vcpu_ioctl_run+0x254/0x7c0 >>>>>>>> [  192.895726]  kvm_vcpu_ioctl+0x174/0xb40 >>>>>>>> [  192.899645]  __arm64_sys_ioctl+0xb0/0x120 >>>>>>>> [  192.903745]  invoke_syscall.constprop.0+0xa8/0x100 >>>>>>>> [  192.908639]  do_el0_svc+0xb8/0xe0 >>>>>>>> [  192.912022]  el0_svc+0x48/0x1f8 >>>>>>>> [  192.915228]  el0t_64_sync_handler+0xa0/0xe8 >>>>>>>> [  192.919500]  el0t_64_sync+0x1ac/0x1b0 >>>>>>>> [  192.923243] SMP: stopping secondary CPUs >>>>>>>> [  192.927653] Starting crashdump kernel... >>>>>>>> [  192.931658] Bye! >>>>>>>> >>>>>>> >>>>>>> With the following changes applied after PATCH[01-05] on top of v7.3.rc4, the crash >>>>>>> is avoided. >>>>>>> >>>>>>> In arch/arm64/include/asm/kvm_host.h: >>>>>>> >>>>>>> -#define kvm_vm_is_protected(kvm)       ((kvm)->arch.vm_flavor >= __VM_PROTECTED) >>>>>>> +#define kvm_vm_is_protected(kvm)       \ >>>>>>> +       (is_protected_kvm_enabled() && (kvm)->arch.vm_flavor >= __VM_PROTECTED) >>>>>> >>>>>> That only papers over the problem. We can't use the vcpu_is_* >>>>>> constructs from nvhe hyp, without converting the vcpu->kvm to >>>>>> the hyp address, before accessing it. The fix is a bit more >>>>>> involved. One option is to define the vcpu_is_* helpers only >>>>>> for the !NVHE hyp code in the kvm_host.h (to avoid pulling >>>>>> in the asm/kvm_mmu.h in to kvm_host.h and then make a mess >>>>>> with header dependencies) and define the NVHE version in >>>>>> asm/kvm_hyp.h. Something like : >>>>>> >>>>>> >>>>>> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/ include/ asm/kvm_host.h >>>>>> index 46a7f6c1e426c..4016d09ed39c3 100644 >>>>>> --- a/arch/arm64/include/asm/kvm_host.h >>>>>> +++ b/arch/arm64/include/asm/kvm_host.h >>>>>> @@ -1545,11 +1545,14 @@ struct kvm *kvm_arch_alloc_vm(void); >>>>>>   #define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS_RANGE >>>>>> >>>>>>   #define kvm_vm_is_protected(kvm)       ((kvm)->arch.vm_flavor >= __VM_PROTECTED) >>>>>> + >>>>>> +#ifndef __KVM_NVHE_HYPERVISOR__ >>>>>>   #define vcpu_is_protected(vcpu) kvm_vm_is_protected((vcpu)->kvm) >>>>>> +#define vcpu_is_protected_pkvm(vcpu) kvm_vm_is_protected_pkvm((vcpu)- >kvm) >>>>>> +#endif >>>>>> >>>>>>   #define kvm_vm_is_protected_pkvm(kvm)          \ >>>>>>          (is_protected_kvm_enabled() && ((kvm)->arch.vm_flavor == VM_PROTECTED_PKVM)) >>>>>> -#define vcpu_is_protected_pkvm(vcpu) kvm_vm_is_protected_pkvm(vcpu- >kvm) >>>>>> >>>>>>   #define kvm_vm_is_unprotected_pkvm(kvm)                \ >>>>>>          (is_protected_kvm_enabled() && ((kvm)->arch.vm_flavor == VM_PKVM)) >>>>>> diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/ asm/kvm_hyp.h >>>>>> index 4974492744cc8..3bf87e81af430 100644 >>>>>> --- a/arch/arm64/include/asm/kvm_hyp.h >>>>>> +++ b/arch/arm64/include/asm/kvm_hyp.h >>>>>> @@ -137,6 +137,19 @@ int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long *per_cpu_bas >>>>>>   void __noreturn __host_enter(struct kvm_cpu_context *host_ctxt); >>>>>>   #endif >>>>>> >>>>>> +#ifdef __KVM_NVHE_HYPERVISOR__ >>>>>> +#define vcpu_is_protected(vcpu)        \ >>>>>> + ({                                                              \ >>>>>> +               struct kvm *__kvm = READ_ONCE((vcpu)- >kvm);             \ >>>>>> +               __kvm && kvm_vm_is_protected((kern_hyp_va(__kvm)));     \ >>>>>> +       }) >>>>>> +#define vcpu_is_protected_pkvm(vcpu)                                   \ >>>>>> + ({                                                              \ >>>>>> +               struct kvm *__kvm = READ_ONCE((vcpu)- >kvm);             \ >>>>>> +               __kvm && kvm_vm_is_protected_pkvm((kern_hyp_va(__kvm)));\ >>>>>> +       }) >>>>>> +#endif >>>>>> + >>>>>> >>>>>> >>>>>> Or explicitly convert all nvhe accessors to a new "nvhe_vcpu_is_protected" >>>>>> >>>>>> The second one sounds like a better option to me. >>>>>> >>>>> >>>>> We just need to include "asm/kvm_mmu.h" to "arch/arm64/mmio.c". With it, >>>>> we can have unified functions (macros) in kvm_host.h to accomodate all >>>>> cases, like below. >>>>> >>>>> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/ asm/ kvm_host.h >>>>> index 9b1cf9c59e81..b9c9a9f203f9 100644 >>>>> --- a/arch/arm64/include/asm/kvm_host.h >>>>> +++ b/arch/arm64/include/asm/kvm_host.h >>>>> @@ -1514,11 +1514,36 @@ struct kvm *kvm_arch_alloc_vm(void); >>>>>   #define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS_RANGE >>>>> >>>>>   #define kvm_vm_is_protected(kvm)       ((kvm)->arch.vm_flavor >= __VM_PROTECTED) >>>>> -#define vcpu_is_protected(vcpu) kvm_vm_is_protected((vcpu)->kvm) >>>>> +#define vcpu_is_protected(vcpu)                                                \ >>>>> + ({                                                              \ >>>>> +               struct kvm *__kvm = READ_ONCE((vcpu)- >kvm);             \ >>>>> +               bool __protected = false;                               \ >>>>> +                                                                       \ >>>>> +               if (__kvm) {                                            \ >>>>> +                       if (is_nvhe_hyp_code())                         \ >>> >>> This needs to be : >>>                if (is_nvhe_hyp_code() && !is_protected_kvm_enabled()) >>> >> >> Yes. >> >>>>> +                               __kvm = kern_hyp_va(__kvm);             \ >>> >>> Otherwise, we unnecessarily convert the vcpu->kvm for a hyp_vcpu and >>> that is not going to end well for pKVM. >>> >> >> Yes. kern_hyp_va() isn't needed when is_protected_kvm_enabled() is true. > > nit : It is not that it is needed, but it is incorrect to convert the vcpu->kvm which is already a HYP VA via kern_hyp_va() which is not > idempotent and thus we end up accessing something junk. > Yes. >> Besides, vcpu_is_protected_pkvm() can be further simplifed by fully exploiting >> the check (is_protected_kvm_enabled()) done in vcpu_is_protected_pkvm(), >> see below. > > Good point. > >> >>> Cheers >>> Suzuki >>> >>> >>>>> +                       __protected = kvm_vm_is_protected(__kvm);       \ >>>>> +               }                                                       \ >>>>> +                                                                       \ >>>>> + __protected;                                            \ >>>>> +        }) >>>>> + >>>>> >>>>>   #define kvm_vm_is_protected_pkvm(kvm)          \ >>>>>          (is_protected_kvm_enabled() && ((kvm)->arch.vm_flavor == VM_PROTECTED_PKVM)) >>>>> -#define vcpu_is_protected_pkvm(vcpu) kvm_vm_is_protected_pkvm(vcpu- >kvm) >>>>> +#define vcpu_is_protected_pkvm(vcpu)                                   \ >>>>> + ({                                                              \ >>>>> +               struct kvm *__kvm = READ_ONCE((vcpu)- >kvm);             \ >>>>> +               bool __protected = false;                               \ >>>>> +                                                                       \ >>>>> +               if (__kvm) {                                            \ >>>>> +                       if (is_nvhe_hyp_code())                         \ >>>>> +                               __kvm = kern_hyp_va(__kvm);             \ >>>>> +                       __protected = kvm_vm_is_protected_pkvm(__kvm);  \ >>>>> +               }                                                       \ >>>>> +                                                                       \ >>>>> + __protected;                                            \ >>>>> +        }) >> >> This can be further simplified by fully expliting the check (is_protected_kvm_enabled()) >> in kvm_vm_is_protected_pkvm(), as below. The point is that the check is_protected_kvm_enabled() >> gurantees that kern_hyp_va() isn't needed. >> >> #define vcpu_is_protected_pkvm(vcpu)                                    \ >>          ({                                                              \ >>                  struct kvm *__kvm = READ_ONCE((vcpu)->kvm);             \ >>                  bool __protected = false;                               \ >>                                                                          \ >>                  if (__kvm)                                              \ >>                          __protected = kvm_vm_is_protected_pkvm(__kvm);  \ >>                                                                          \ >>                  __protected;                                            \ >>          }) >> > > Ack, I have reduced this to: > > > /* >  * Rely on is_protected_kvm_enabled() check in kvm_vm_is_protected_pkvm() to >  * make sure the vcpu->kvm is always valid VA in the context >  */ > #define vcpu_is_protected_pkvm(vcpu)                                    \ >         ({                                                              \ >                 struct kvm *__kvm = READ_ONCE((vcpu)->kvm);             \ >                                                                         \ >                 (__kvm) && kvm_vm_is_protected_pkvm(__kvm));            \ >         }) > Parentheses for the local variable '__kvm' can be dropped. With this, this looks good to me. (__kvm && kvm_vm_is_protected_pkvm(__kvm)); Thanks, Gavin > > Cheers > Suzuki > >>>>> >>>>>   #define kvm_vm_is_unprotected_pkvm(kvm)                \ >>>>>          (is_protected_kvm_enabled() && ((kvm)->arch.vm_flavor == VM_PKVM)) >>>>> diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c >>>>> index d1c3a352d5a2..ab1d2fef9a52 100644 >>>>> --- a/arch/arm64/kvm/mmio.c >>>>> +++ b/arch/arm64/kvm/mmio.c >>>>> @@ -6,6 +6,7 @@ >>>>> >>>>>   #include >>>>>   #include >>>>> +#include >>>>>   #include >>>>> >>>>>   #include "trace.h" >>>>> >>>> >>>> Thanks Gavin, that works and looks neat. I will incorporate it. >>>> >> >> Thanks, >> Gavin >> >