Commit f55ffaf8 authored by Quan Zhou's avatar Quan Zhou Committed by Anup Patel
Browse files

RISC-V: KVM: Enable ring-based dirty memory tracking 



Enable ring-based dirty memory tracking on riscv:

- Enable CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL as riscv is weakly
  ordered.
- Set KVM_DIRTY_LOG_PAGE_OFFSET for the ring buffer's physical page
  offset.
- Add a check to kvm_vcpu_kvm_riscv_check_vcpu_requests for checking
  whether the dirty ring is soft full.

To handle vCPU requests that cause exits to userspace, modified the
`kvm_riscv_check_vcpu_requests` to return a value (currently only
returns 0 or 1).

Signed-off-by: default avatarQuan Zhou <zhouquan@iscas.ac.cn>
Reviewed-by: default avatarAnup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20e116efb1f7aff211dd8e3cf8990c5521ed5f34.1749810735.git.zhouquan@iscas.ac.cn


Signed-off-by: default avatarAnup Patel <anup@brainfault.org>
parent 7826c8f3

Documentation/virt/kvm/api.rst

+1 −1
Original line number Diff line number Diff line
@@ -8373,7 +8373,7 @@ core crystal clock frequency, if a non-zero CPUID 0x15 is exposed to the guest. 
7.36 KVM_CAP_DIRTY_LOG_RING/KVM_CAP_DIRTY_LOG_RING_ACQ_REL

----------------------------------------------------------



:Architectures: x86, arm64

:Architectures: x86, arm64, riscv

:Type: vm

:Parameters: args[0] - size of the dirty log ring

arch/riscv/include/uapi/asm/kvm.h

+1 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#define __KVM_HAVE_IRQ_LINE



#define KVM_COALESCED_MMIO_PAGE_OFFSET 1

#define KVM_DIRTY_LOG_PAGE_OFFSET 64



#define KVM_INTERRUPT_SET	-1U

#define KVM_INTERRUPT_UNSET	-2U

arch/riscv/kvm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ config KVM 
	select HAVE_KVM_MSI

	select HAVE_KVM_VCPU_ASYNC_IOCTL

	select HAVE_KVM_READONLY_MEM

	select HAVE_KVM_DIRTY_RING_ACQ_REL

	select KVM_COMMON

	select KVM_GENERIC_DIRTYLOG_READ_PROTECT

	select KVM_GENERIC_HARDWARE_ENABLING

arch/riscv/kvm/vcpu.c

+16 −2
Original line number Diff line number Diff line
@@ -682,7 +682,14 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) 
	}

}



static void kvm_riscv_check_vcpu_requests(struct kvm_vcpu *vcpu)

/**

 * check_vcpu_requests - check and handle pending vCPU requests

 * @vcpu:	the VCPU pointer

 *

 * Return: 1 if we should enter the guest

 *	    0 if we should exit to userspace

 */

static int kvm_riscv_check_vcpu_requests(struct kvm_vcpu *vcpu)

{

	struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu);
@@ -723,7 +730,12 @@ static void kvm_riscv_check_vcpu_requests(struct kvm_vcpu *vcpu) 


		if (kvm_check_request(KVM_REQ_STEAL_UPDATE, vcpu))

			kvm_riscv_vcpu_record_steal_time(vcpu);



		if (kvm_dirty_ring_check_request(vcpu))

			return 0;

	}



	return 1;

}



static void kvm_riscv_update_hvip(struct kvm_vcpu *vcpu)
@@ -905,7 +917,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) 


		kvm_riscv_gstage_vmid_update(vcpu);



		kvm_riscv_check_vcpu_requests(vcpu);

		ret = kvm_riscv_check_vcpu_requests(vcpu);

		if (ret <= 0)

			continue;



		preempt_disable();