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From: Sean Christopherson <seanjc@google.com>
To: Marc Zyngier <maz@kernel.org>,
	Oliver Upton <oliver.upton@linux.dev>,
	 Tianrui Zhao <zhaotianrui@loongson.cn>,
	Bibo Mao <maobibo@loongson.cn>,
	 Huacai Chen <chenhuacai@kernel.org>,
	Madhavan Srinivasan <maddy@linux.ibm.com>,
	 Anup Patel <anup@brainfault.org>, Paul Walmsley <pjw@kernel.org>,
	 Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	 Christian Borntraeger <borntraeger@linux.ibm.com>,
	Janosch Frank <frankja@linux.ibm.com>,
	 Claudio Imbrenda <imbrenda@linux.ibm.com>,
	Sean Christopherson <seanjc@google.com>,
	 Paolo Bonzini <pbonzini@redhat.com>,
	"Kirill A. Shutemov" <kas@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
	 kvm@vger.kernel.org, loongarch@lists.linux.dev,
	linux-mips@vger.kernel.org,  linuxppc-dev@lists.ozlabs.org,
	kvm-riscv@lists.infradead.org,  linux-riscv@lists.infradead.org,
	x86@kernel.org, linux-coco@lists.linux.dev,
	 linux-kernel@vger.kernel.org, Ira Weiny <ira.weiny@intel.com>,
	 Kai Huang <kai.huang@intel.com>,
	Binbin Wu <binbin.wu@linux.intel.com>,
	 Michael Roth <michael.roth@amd.com>,
	Yan Zhao <yan.y.zhao@intel.com>,
	 Vishal Annapurve <vannapurve@google.com>,
	Rick Edgecombe <rick.p.edgecombe@intel.com>,
	 Ackerley Tng <ackerleytng@google.com>
Subject: [PATCH v4 02/28] KVM: Rename kvm_arch_vcpu_async_ioctl() to kvm_arch_vcpu_unlocked_ioctl()
Date: Thu, 30 Oct 2025 13:09:25 -0700	[thread overview]
Message-ID: <20251030200951.3402865-3-seanjc@google.com> (raw)
In-Reply-To: <20251030200951.3402865-1-seanjc@google.com>

Rename the "async" ioctl API to "unlocked" so that upcoming usage in x86's
TDX code doesn't result in a massive misnomer.  To avoid having to retry
SEAMCALLs, TDX needs to acquire kvm->lock *and* all vcpu->mutex locks, and
acquiring all of those locks after/inside the current vCPU's mutex is a
non-starter.  However, TDX also needs to acquire the vCPU's mutex and load
the vCPU, i.e. the handling is very much not async to the vCPU.

No functional change intended.

Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/arm64/kvm/arm.c       | 4 ++--
 arch/loongarch/kvm/vcpu.c  | 4 ++--
 arch/mips/kvm/mips.c       | 4 ++--
 arch/powerpc/kvm/powerpc.c | 4 ++--
 arch/riscv/kvm/vcpu.c      | 4 ++--
 arch/s390/kvm/kvm-s390.c   | 4 ++--
 arch/x86/kvm/x86.c         | 4 ++--
 include/linux/kvm_host.h   | 4 ++--
 virt/kvm/kvm_main.c        | 6 +++---
 9 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index ef5bf57f79b7..cf23f6b07ec7 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1835,8 +1835,8 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 	return r;
 }
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp, unsigned int ioctl,
-			       unsigned long arg)
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+				  unsigned long arg)
 {
 	return -ENOIOCTLCMD;
 }
diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index 30e3b089a596..9a5844e85fd3 100644
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -1471,8 +1471,8 @@ int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
 	return 0;
 }
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp,
-			       unsigned int ioctl, unsigned long arg)
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+				  unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
 	struct kvm_vcpu *vcpu = filp->private_data;
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index a75587018f44..b0fb92fda4d4 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -895,8 +895,8 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
 	return r;
 }
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp, unsigned int ioctl,
-			       unsigned long arg)
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+				  unsigned long arg)
 {
 	struct kvm_vcpu *vcpu = filp->private_data;
 	void __user *argp = (void __user *)arg;
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 2ba057171ebe..9a89a6d98f97 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -2028,8 +2028,8 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
 	return -EINVAL;
 }
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp,
-			       unsigned int ioctl, unsigned long arg)
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+				  unsigned long arg)
 {
 	struct kvm_vcpu *vcpu = filp->private_data;
 	void __user *argp = (void __user *)arg;
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index bccb919ca615..a4bd6077eecc 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -238,8 +238,8 @@ vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
 	return VM_FAULT_SIGBUS;
 }
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp,
-			       unsigned int ioctl, unsigned long arg)
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+				  unsigned long arg)
 {
 	struct kvm_vcpu *vcpu = filp->private_data;
 	void __user *argp = (void __user *)arg;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 16ba04062854..8c4caa5f2fcd 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -5730,8 +5730,8 @@ static long kvm_s390_vcpu_memsida_op(struct kvm_vcpu *vcpu,
 	return r;
 }
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp,
-			       unsigned int ioctl, unsigned long arg)
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+				  unsigned long arg)
 {
 	struct kvm_vcpu *vcpu = filp->private_data;
 	void __user *argp = (void __user *)arg;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ca5ba2caf314..b85cb213a336 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7240,8 +7240,8 @@ static int kvm_vm_ioctl_set_clock(struct kvm *kvm, void __user *argp)
 	return 0;
 }
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp, unsigned int ioctl,
-			       unsigned long arg)
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+				  unsigned long arg)
 {
 	return -ENOIOCTLCMD;
 }
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 7186b2ae4b57..d93f75b05ae2 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1557,6 +1557,8 @@ long kvm_arch_dev_ioctl(struct file *filp,
 			unsigned int ioctl, unsigned long arg);
 long kvm_arch_vcpu_ioctl(struct file *filp,
 			 unsigned int ioctl, unsigned long arg);
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp,
+				  unsigned int ioctl, unsigned long arg);
 vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf);
 
 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext);
@@ -2437,8 +2439,6 @@ static inline bool kvm_arch_no_poll(struct kvm_vcpu *vcpu)
 }
 #endif /* CONFIG_HAVE_KVM_NO_POLL */
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp,
-			       unsigned int ioctl, unsigned long arg);
 void kvm_arch_guest_memory_reclaimed(struct kvm *kvm);
 
 #ifdef CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4845e5739436..9eca084bdcbe 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4434,10 +4434,10 @@ static long kvm_vcpu_ioctl(struct file *filp,
 		return r;
 
 	/*
-	 * Some architectures have vcpu ioctls that are asynchronous to vcpu
-	 * execution; mutex_lock() would break them.
+	 * Let arch code handle select vCPU ioctls without holding vcpu->mutex,
+	 * e.g. to support ioctls that can run asynchronous to vCPU execution.
 	 */
-	r = kvm_arch_vcpu_async_ioctl(filp, ioctl, arg);
+	r = kvm_arch_vcpu_unlocked_ioctl(filp, ioctl, arg);
 	if (r != -ENOIOCTLCMD)
 		return r;
 
-- 
2.51.1.930.gacf6e81ea2-goog


  parent reply	other threads:[~2025-10-30 20:10 UTC|newest]

Thread overview: 66+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-30 20:09 [PATCH v4 00/28] KVM: x86/mmu: TDX post-populate cleanups Sean Christopherson
2025-10-30 20:09 ` [PATCH v4 01/28] KVM: Make support for kvm_arch_vcpu_async_ioctl() mandatory Sean Christopherson
2025-10-30 20:09 ` Sean Christopherson [this message]
2025-10-30 20:09 ` [PATCH v4 03/28] KVM: TDX: Drop PROVE_MMU=y sanity check on to-be-populated mappings Sean Christopherson
2025-10-30 20:09 ` [PATCH v4 04/28] KVM: x86/mmu: Add dedicated API to map guest_memfd pfn into TDP MMU Sean Christopherson
2025-10-31  7:58   ` Binbin Wu
2025-10-30 20:09 ` [PATCH v4 05/28] KVM: x86/mmu: WARN if KVM attempts to map into an invalid TDP MMU root Sean Christopherson
2025-10-30 22:17   ` Huang, Kai
2025-10-30 20:09 ` [PATCH v4 06/28] Revert "KVM: x86/tdp_mmu: Add a helper function to walk down the TDP MMU" Sean Christopherson
2025-10-30 20:09 ` [PATCH v4 07/28] KVM: x86/mmu: Rename kvm_tdp_map_page() to kvm_tdp_page_prefault() Sean Christopherson
2025-10-30 20:09 ` [PATCH v4 08/28] KVM: TDX: Drop superfluous page pinning in S-EPT management Sean Christopherson
2025-10-31  8:29   ` Yan Zhao
2025-10-31 17:12     ` Sean Christopherson
2025-10-30 20:09 ` [PATCH v4 09/28] KVM: TDX: Return -EIO, not -EINVAL, on a KVM_BUG_ON() condition Sean Christopherson
2025-10-30 22:20   ` Huang, Kai
2025-10-30 20:09 ` [PATCH v4 10/28] KVM: TDX: Fold tdx_sept_drop_private_spte() into tdx_sept_remove_private_spte() Sean Christopherson
2025-10-31  8:23   ` Yan Zhao
2025-10-30 20:09 ` [PATCH v4 11/28] KVM: x86/mmu: Drop the return code from kvm_x86_ops.remove_external_spte() Sean Christopherson
2025-10-30 22:26   ` Huang, Kai
2025-10-30 20:09 ` [PATCH v4 12/28] KVM: TDX: WARN if mirror SPTE doesn't have full RWX when creating S-EPT mapping Sean Christopherson
2025-10-30 22:59   ` Huang, Kai
2025-10-30 23:40     ` Sean Christopherson
2025-10-30 23:59       ` Huang, Kai
2025-10-31  8:19   ` Binbin Wu
2025-10-30 20:09 ` [PATCH v4 13/28] KVM: TDX: Avoid a double-KVM_BUG_ON() in tdx_sept_zap_private_spte() Sean Christopherson
2025-10-30 20:09 ` [PATCH v4 14/28] KVM: TDX: Use atomic64_dec_return() instead of a poor equivalent Sean Christopherson
2025-10-30 20:09 ` [PATCH v4 15/28] KVM: TDX: Fold tdx_mem_page_record_premap_cnt() into its sole caller Sean Christopherson
2025-10-30 20:09 ` [PATCH v4 16/28] KVM: TDX: ADD pages to the TD image while populating mirror EPT entries Sean Christopherson
2025-10-31  8:54   ` Binbin Wu
2025-10-30 20:09 ` [PATCH v4 17/28] KVM: TDX: Fold tdx_sept_zap_private_spte() into tdx_sept_remove_private_spte() Sean Christopherson
2025-10-31  8:56   ` Binbin Wu
2025-10-30 20:09 ` [PATCH v4 18/28] KVM: TDX: Combine KVM_BUG_ON + pr_tdx_error() into TDX_BUG_ON() Sean Christopherson
2025-10-30 23:20   ` Huang, Kai
2025-10-31  8:58   ` Binbin Wu
2025-10-30 20:09 ` [PATCH v4 19/28] KVM: TDX: Derive error argument names from the local variable names Sean Christopherson
2025-10-31  9:00   ` Binbin Wu
2025-10-30 20:09 ` [PATCH v4 20/28] KVM: TDX: Assert that mmu_lock is held for write when removing S-EPT entries Sean Christopherson
2025-10-30 23:03   ` Huang, Kai
2025-10-31  9:05   ` Binbin Wu
2025-10-30 20:09 ` [PATCH v4 21/28] KVM: TDX: Add macro to retry SEAMCALLs when forcing vCPUs out of guest Sean Christopherson
2025-10-30 23:05   ` Huang, Kai
2025-10-31  9:08   ` Binbin Wu
2025-10-30 20:09 ` [PATCH v4 22/28] KVM: TDX: Add tdx_get_cmd() helper to get and validate sub-ioctl command Sean Christopherson
2025-10-31  9:11   ` Binbin Wu
2025-10-30 20:09 ` [PATCH v4 23/28] KVM: TDX: Convert INIT_MEM_REGION and INIT_VCPU to "unlocked" vCPU ioctl Sean Christopherson
2025-10-31  9:15   ` Binbin Wu
2025-10-30 20:09 ` [PATCH v4 24/28] KVM: TDX: Use guard() to acquire kvm->lock in tdx_vm_ioctl() Sean Christopherson
2025-10-31  9:17   ` Binbin Wu
2025-10-30 20:09 ` [PATCH v4 25/28] KVM: TDX: Don't copy "cmd" back to userspace for KVM_TDX_CAPABILITIES Sean Christopherson
2025-10-30 23:06   ` Huang, Kai
2025-10-30 20:09 ` [PATCH v4 26/28] KVM: TDX: Guard VM state transitions with "all" the locks Sean Christopherson
2025-10-30 23:08   ` Huang, Kai
2025-10-31  8:26   ` Yan Zhao
2025-10-31 17:34     ` Sean Christopherson
2025-11-03  1:36       ` Yan Zhao
2025-10-30 20:09 ` [PATCH v4 27/28] KVM: TDX: Bug the VM if extending the initial measurement fails Sean Christopherson
2025-10-30 23:09   ` Huang, Kai
2025-11-04  6:16   ` Binbin Wu
2025-11-04 18:02     ` Sean Christopherson
2025-10-30 20:09 ` [PATCH v4 28/28] KVM: TDX: Fix list_add corruption during vcpu_load() Sean Christopherson
2025-10-30 23:12   ` Huang, Kai
2025-10-30 23:19 ` [PATCH v4 00/28] KVM: x86/mmu: TDX post-populate cleanups Huang, Kai
2025-10-31  8:54 ` Yan Zhao
2025-10-31 17:28 ` Edgecombe, Rick P
2025-11-04 17:58   ` Sean Christopherson
2025-11-10 15:37 ` Sean Christopherson

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