diff mbox series

[RFC,16/48] RISC-V: KVM: Skip most VCPU requests for TVMs

Message ID	20230419221716.3603068-17-atishp@rivosinc.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@vger.kernel.org> From: Atish Patra <atishp@rivosinc.com> To: linux-kernel@vger.kernel.org Cc: Atish Patra <atishp@rivosinc.com>, Alexandre Ghiti <alex@ghiti.fr>, Andrew Jones <ajones@ventanamicro.com>, Andrew Morton <akpm@linux-foundation.org>, Anup Patel <anup@brainfault.org>, Atish Patra <atishp@atishpatra.org>, =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= <bjorn@rivosinc.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>, Sean Christopherson <seanjc@google.com>, linux-coco@lists.linux.dev, Dylan Reid <dylan@rivosinc.com>, abrestic@rivosinc.com, Samuel Ortiz <sameo@rivosinc.com>, Christoph Hellwig <hch@infradead.org>, Conor Dooley <conor.dooley@microchip.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Guo Ren <guoren@kernel.org>, Heiko Stuebner <heiko@sntech.de>, Jiri Slaby <jirislaby@kernel.org>, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, Mayuresh Chitale <mchitale@ventanamicro.com>, Palmer Dabbelt <palmer@dabbelt.com>, Paolo Bonzini <pbonzini@redhat.com>, Paul Walmsley <paul.walmsley@sifive.com>, Rajnesh Kanwal <rkanwal@rivosinc.com>, Uladzislau Rezki <urezki@gmail.com> Subject: [RFC 16/48] RISC-V: KVM: Skip most VCPU requests for TVMs Date: Wed, 19 Apr 2023 15:16:44 -0700 Message-Id: <20230419221716.3603068-17-atishp@rivosinc.com> In-Reply-To: <20230419221716.3603068-1-atishp@rivosinc.com> References: <20230419221716.3603068-1-atishp@rivosinc.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	RISC-V CoVE support \| expand [RFC,00/48] RISC-V CoVE support [RFC,01/48] mm/vmalloc: Introduce arch hooks to notify ioremap/unmap changes [RFC,02/48] RISC-V: KVM: Improve KVM error reporting to the user space [RFC,03/48] RISC-V: KVM: Invoke aia_update with preempt disabled/irq enabled [RFC,04/48] RISC-V: KVM: Add a helper function to get pgd size [RFC,05/48] RISC-V: Add COVH SBI extensions definitions [RFC,06/48] RISC-V: KVM: Implement COVH SBI extension [RFC,07/48] RISC-V: KVM: Add a barebone CoVE implementation [RFC,08/48] RISC-V: KVM: Add UABI to support static memory region attestation [RFC,09/48] RISC-V: KVM: Add CoVE related nacl helpers [RFC,10/48] RISC-V: KVM: Implement static memory region measurement [RFC,11/48] RISC-V: KVM: Use the new VM IOCTL for measuring pages [RFC,12/48] RISC-V: KVM: Exit to the user space for trap redirection [RFC,13/48] RISC-V: KVM: Return early for gstage modifications [RFC,14/48] RISC-V: KVM: Skip dirty logging updates for TVM [RFC,15/48] RISC-V: KVM: Add a helper function to trigger fence ops [RFC,16/48] RISC-V: KVM: Skip most VCPU requests for TVMs [RFC,17/48] RISC-V : KVM: Skip vmid/hgatp management for TVMs [RFC,18/48] RISC-V: KVM: Skip TLB management for TVMs [RFC,19/48] RISC-V: KVM: Register memory regions as confidential for TVMs [RFC,20/48] RISC-V: KVM: Add gstage mapping for TVMs [RFC,21/48] RISC-V: KVM: Handle SBI call forward from the TSM [RFC,22/48] RISC-V: KVM: Implement vcpu load/put functions for CoVE guests [RFC,23/48] RISC-V: KVM: Wireup TVM world switch [RFC,24/48] RISC-V: KVM: Update timer functionality for TVMs. [RFC,25/48] RISC-V: KVM: Skip HVIP update for TVMs [RFC,26/48] RISC-V: Add COVI extension definitions [RFC,27/48] RISC-V: KVM: Implement COVI SBI extension [RFC,28/48] RISC-V: KVM: Add interrupt management functions for TVM [RFC,29/48] RISC-V: KVM: Skip AIA CSR updates for TVMs [RFC,30/48] RISC-V: KVM: Perform limited operations in hardware enable/disable [RFC,31/48] RISC-V: KVM: Indicate no support user space emulated IRQCHIP [RFC,32/48] RISC-V: KVM: Add AIA support for TVMs [RFC,33/48] RISC-V: KVM: Hookup TVM VCPU init/destroy [RFC,34/48] RISC-V: KVM: Initialize CoVE [RFC,35/48] RISC-V: KVM: Add TVM init/destroy calls [RFC,36/48] RISC-V: KVM: Read/write gprs from/to shmem in case of TVM VCPU. [RFC,37/48] RISC-V: Add COVG SBI extension definitions [RFC,38/48] RISC-V: Add CoVE guest config and helper functions [RFC,39/48] RISC-V: Implement COVG SBI extension [RFC,40/48] RISC-V: COVE: Add COVH invalidate, validate, promote, demote and remove APIs. [RFC,41/48] RISC-V: KVM: Add host side support to handle COVG SBI calls. [RFC,42/48] RISC-V: Allow host to inject any ext interrupt id to a CoVE guest. [RFC,43/48] RISC-V: Add base memory encryption functions. [RFC,44/48] RISC-V: Add cc_platform_has() for RISC-V for CoVE [RFC,45/48] RISC-V: ioremap: Implement for arch specific ioremap hooks [RFC,46/48] riscv/virtio: Have CoVE guests enforce restricted virtio memory access. [RFC,47/48] RISC-V: Add shared bounce buffer to support DBCN for CoVE Guest. [RFC,48/48] drivers/hvc: sbi: Disable HVC console for TVMs

Commit Message

Atish Kumar Patra April 19, 2023, 10:16 p.m. UTC

Currently, KVM manages TLB shootdown, hgatp updates and
fence.i through vcpu requests.

TLB shootdown for the TVMs happens in co-ordination with TSM.
The fence.i & hgatp updates are directly managed by the TSM.
There is no need to issue these requests directly for TVMs.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 arch/riscv/kvm/vcpu.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff mbox series

Patch

diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index c53bf98..3b600c6 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -22,6 +22,7 @@ 
 #include <asm/kvm_nacl.h>
 #include <asm/hwcap.h>
 #include <asm/sbi.h>
+#include <asm/kvm_cove.h>
 
 const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
 	KVM_GENERIC_VCPU_STATS(),
@@ -1078,6 +1079,15 @@  static void kvm_riscv_check_vcpu_requests(struct kvm_vcpu *vcpu)
 		if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))
 			kvm_riscv_reset_vcpu(vcpu);
 
+		if (is_cove_vcpu(vcpu)) {
+			/*
+			 * KVM doesn't need to do anything special here
+			 * as the TSM is expected track the tlb version and issue
+			 * hfence when vcpu is scheduled again.
+			 */
+			return;
+		}
+
 		if (kvm_check_request(KVM_REQ_UPDATE_HGATP, vcpu))
 			kvm_riscv_gstage_update_hgatp(vcpu);