Commit 54e43320 authored by Anup Patel's avatar Anup Patel Committed by Anup Patel
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RISC-V: KVM: Initial skeletal support for AIA 



To incrementally implement AIA support, we first add minimal skeletal
support which only compiles and detects AIA hardware support at the
boot-time but does not provide any functionality.

Signed-off-by: default avatarAnup Patel <apatel@ventanamicro.com>
Reviewed-by: default avatarAtish Patra <atishp@rivosinc.com>
Reviewed-by: default avatarAndrew Jones <ajones@ventanamicro.com>
Signed-off-by: default avatarAnup Patel <anup@brainfault.org>
parent e290dbb7

arch/riscv/include/asm/hwcap.h

+6 −0
Original line number Diff line number Diff line
@@ -48,6 +48,12 @@ 
#define RISCV_ISA_EXT_MAX		64

#define RISCV_ISA_EXT_NAME_LEN_MAX	32



#ifdef CONFIG_RISCV_M_MODE

#define RISCV_ISA_EXT_SxAIA		RISCV_ISA_EXT_SMAIA

#else

#define RISCV_ISA_EXT_SxAIA		RISCV_ISA_EXT_SSAIA

#endif



#ifndef __ASSEMBLY__



#include <linux/jump_label.h>

arch/riscv/include/asm/kvm_aia.h

0 → 100644
+109 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only */

/*

 * Copyright (C) 2021 Western Digital Corporation or its affiliates.

 * Copyright (C) 2022 Ventana Micro Systems Inc.

 *

 * Authors:

 *	Anup Patel <apatel@ventanamicro.com>

 */



#ifndef __KVM_RISCV_AIA_H

#define __KVM_RISCV_AIA_H



#include <linux/jump_label.h>

#include <linux/kvm_types.h>



struct kvm_aia {

	/* In-kernel irqchip created */

	bool		in_kernel;



	/* In-kernel irqchip initialized */

	bool		initialized;

};



struct kvm_vcpu_aia {

};



#define kvm_riscv_aia_initialized(k)	((k)->arch.aia.initialized)



#define irqchip_in_kernel(k)		((k)->arch.aia.in_kernel)



DECLARE_STATIC_KEY_FALSE(kvm_riscv_aia_available);

#define kvm_riscv_aia_available() \

	static_branch_unlikely(&kvm_riscv_aia_available)



static inline void kvm_riscv_vcpu_aia_flush_interrupts(struct kvm_vcpu *vcpu)

{

}



static inline void kvm_riscv_vcpu_aia_sync_interrupts(struct kvm_vcpu *vcpu)

{

}



static inline bool kvm_riscv_vcpu_aia_has_interrupts(struct kvm_vcpu *vcpu,

						     u64 mask)

{

	return false;

}



static inline void kvm_riscv_vcpu_aia_update_hvip(struct kvm_vcpu *vcpu)

{

}



static inline void kvm_riscv_vcpu_aia_load(struct kvm_vcpu *vcpu, int cpu)

{

}



static inline void kvm_riscv_vcpu_aia_put(struct kvm_vcpu *vcpu)

{

}



static inline int kvm_riscv_vcpu_aia_get_csr(struct kvm_vcpu *vcpu,

					     unsigned long reg_num,

					     unsigned long *out_val)

{

	*out_val = 0;

	return 0;

}



static inline int kvm_riscv_vcpu_aia_set_csr(struct kvm_vcpu *vcpu,

					     unsigned long reg_num,

					     unsigned long val)

{

	return 0;

}



#define KVM_RISCV_VCPU_AIA_CSR_FUNCS



static inline int kvm_riscv_vcpu_aia_update(struct kvm_vcpu *vcpu)

{

	return 1;

}



static inline void kvm_riscv_vcpu_aia_reset(struct kvm_vcpu *vcpu)

{

}



static inline int kvm_riscv_vcpu_aia_init(struct kvm_vcpu *vcpu)

{

	return 0;

}



static inline void kvm_riscv_vcpu_aia_deinit(struct kvm_vcpu *vcpu)

{

}



static inline void kvm_riscv_aia_init_vm(struct kvm *kvm)

{

}



static inline void kvm_riscv_aia_destroy_vm(struct kvm *kvm)

{

}



void kvm_riscv_aia_enable(void);

void kvm_riscv_aia_disable(void);

int kvm_riscv_aia_init(void);

void kvm_riscv_aia_exit(void);



#endif

arch/riscv/include/asm/kvm_host.h

+7 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/kvm_types.h>

#include <linux/spinlock.h>

#include <asm/hwcap.h>

#include <asm/kvm_aia.h>

#include <asm/kvm_vcpu_fp.h>

#include <asm/kvm_vcpu_insn.h>

#include <asm/kvm_vcpu_sbi.h>
@@ -94,6 +95,9 @@ struct kvm_arch { 


	/* Guest Timer */

	struct kvm_guest_timer timer;



	/* AIA Guest/VM context */

	struct kvm_aia aia;

};



struct kvm_cpu_trap {
@@ -221,6 +225,9 @@ struct kvm_vcpu_arch { 
	/* SBI context */

	struct kvm_vcpu_sbi_context sbi_context;



	/* AIA VCPU context */

	struct kvm_vcpu_aia aia_context;



	/* Cache pages needed to program page tables with spinlock held */

	struct kvm_mmu_memory_cache mmu_page_cache;

arch/riscv/kvm/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -26,3 +26,4 @@ kvm-y += vcpu_sbi_replace.o 
kvm-y += vcpu_sbi_hsm.o

kvm-y += vcpu_timer.o

kvm-$(CONFIG_RISCV_PMU_SBI) += vcpu_pmu.o vcpu_sbi_pmu.o

kvm-y += aia.o

arch/riscv/kvm/aia.c

0 → 100644
+66 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Copyright (C) 2021 Western Digital Corporation or its affiliates.

 * Copyright (C) 2022 Ventana Micro Systems Inc.

 *

 * Authors:

 *	Anup Patel <apatel@ventanamicro.com>

 */



#include <linux/kvm_host.h>

#include <asm/hwcap.h>



DEFINE_STATIC_KEY_FALSE(kvm_riscv_aia_available);



static void aia_set_hvictl(bool ext_irq_pending)

{

	unsigned long hvictl;



	/*

	 * HVICTL.IID == 9 and HVICTL.IPRIO == 0 represents

	 * no interrupt in HVICTL.

	 */



	hvictl = (IRQ_S_EXT << HVICTL_IID_SHIFT) & HVICTL_IID;

	hvictl |= ext_irq_pending;

	csr_write(CSR_HVICTL, hvictl);

}



void kvm_riscv_aia_enable(void)

{

	if (!kvm_riscv_aia_available())

		return;



	aia_set_hvictl(false);

	csr_write(CSR_HVIPRIO1, 0x0);

	csr_write(CSR_HVIPRIO2, 0x0);

#ifdef CONFIG_32BIT

	csr_write(CSR_HVIPH, 0x0);

	csr_write(CSR_HIDELEGH, 0x0);

	csr_write(CSR_HVIPRIO1H, 0x0);

	csr_write(CSR_HVIPRIO2H, 0x0);

#endif

}



void kvm_riscv_aia_disable(void)

{

	if (!kvm_riscv_aia_available())

		return;



	aia_set_hvictl(false);

}



int kvm_riscv_aia_init(void)

{

	if (!riscv_isa_extension_available(NULL, SxAIA))

		return -ENODEV;



	/* Enable KVM AIA support */

	static_branch_enable(&kvm_riscv_aia_available);



	return 0;

}



void kvm_riscv_aia_exit(void)

{

}