On Wed, May 17, 2023 at 3:52 AM Anup Patel <apatel@xxxxxxxxxxxxxxxx> wrote:
>
> We can have AIA IMSIC support for both HS-level and VS-level but
> the VS-level IMSICs are optional. We use the VS-level IMSICs for
> Guest/VM whenever available otherwise we fallback to software
> emulation of AIA IMSIC.
>
> This patch adds in-kernel virtualization of AIA IMSIC.
>
> Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
> ---
> arch/riscv/include/asm/kvm_aia.h | 46 +-
> arch/riscv/kvm/Makefile | 1 +
> arch/riscv/kvm/aia_imsic.c | 913 +++++++++++++++++++++++++++++++
> 3 files changed, 924 insertions(+), 36 deletions(-)
> create mode 100644 arch/riscv/kvm/aia_imsic.c
>
> diff --git a/arch/riscv/include/asm/kvm_aia.h b/arch/riscv/include/asm/kvm_aia.h
> index ba939c0054aa..a4f6ebf90e31 100644
> --- a/arch/riscv/include/asm/kvm_aia.h
> +++ b/arch/riscv/include/asm/kvm_aia.h
> @@ -90,44 +90,18 @@ DECLARE_STATIC_KEY_FALSE(kvm_riscv_aia_available);
>
> extern struct kvm_device_ops kvm_riscv_aia_device_ops;
>
> -static inline void kvm_riscv_vcpu_aia_imsic_release(struct kvm_vcpu *vcpu)
> -{
> -}
> -
> -static inline int kvm_riscv_vcpu_aia_imsic_update(struct kvm_vcpu *vcpu)
> -{
> - return 1;
> -}
> +void kvm_riscv_vcpu_aia_imsic_release(struct kvm_vcpu *vcpu);
> +int kvm_riscv_vcpu_aia_imsic_update(struct kvm_vcpu *vcpu);
>
> #define KVM_RISCV_AIA_IMSIC_TOPEI (ISELECT_MASK + 1)
> -static inline int kvm_riscv_vcpu_aia_imsic_rmw(struct kvm_vcpu *vcpu,
> - unsigned long isel,
> - unsigned long *val,
> - unsigned long new_val,
> - unsigned long wr_mask)
> -{
> - return 0;
> -}
> -
> -static inline void kvm_riscv_vcpu_aia_imsic_reset(struct kvm_vcpu *vcpu)
> -{
> -}
> -
> -static inline int kvm_riscv_vcpu_aia_imsic_inject(struct kvm_vcpu *vcpu,
> - u32 guest_index, u32 offset,
> - u32 iid)
> -{
> - return 0;
> -}
> -
> -static inline int kvm_riscv_vcpu_aia_imsic_init(struct kvm_vcpu *vcpu)
> -{
> - return 0;
> -}
> -
> -static inline void kvm_riscv_vcpu_aia_imsic_cleanup(struct kvm_vcpu *vcpu)
> -{
> -}
> +int kvm_riscv_vcpu_aia_imsic_rmw(struct kvm_vcpu *vcpu, unsigned long isel,
> + unsigned long *val, unsigned long new_val,
> + unsigned long wr_mask);
> +void kvm_riscv_vcpu_aia_imsic_reset(struct kvm_vcpu *vcpu);
> +int kvm_riscv_vcpu_aia_imsic_inject(struct kvm_vcpu *vcpu,
> + u32 guest_index, u32 offset, u32 iid);
> +int kvm_riscv_vcpu_aia_imsic_init(struct kvm_vcpu *vcpu);
> +void kvm_riscv_vcpu_aia_imsic_cleanup(struct kvm_vcpu *vcpu);
>
> int kvm_riscv_aia_aplic_set_attr(struct kvm *kvm, unsigned long type, u32 v);
> int kvm_riscv_aia_aplic_get_attr(struct kvm *kvm, unsigned long type, u32 *v);
> diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile
> index 94c43702c765..c1d1356387ff 100644
> --- a/arch/riscv/kvm/Makefile
> +++ b/arch/riscv/kvm/Makefile
> @@ -29,3 +29,4 @@ kvm-$(CONFIG_RISCV_PMU_SBI) += vcpu_pmu.o vcpu_sbi_pmu.o
> kvm-y += aia.o
> kvm-y += aia_device.o
> kvm-y += aia_aplic.o
> +kvm-y += aia_imsic.o
> diff --git a/arch/riscv/kvm/aia_imsic.c b/arch/riscv/kvm/aia_imsic.c
> new file mode 100644
> index 000000000000..2dc09dcb8ab5
> --- /dev/null
> +++ b/arch/riscv/kvm/aia_imsic.c
> @@ -0,0 +1,913 @@
> +// 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@xxxxxxxxxxxxxxxx>
> + */
> +
> +#include <linux/bitmap.h>
> +#include <linux/kvm_host.h>
> +#include <linux/math.h>
> +#include <linux/spinlock.h>
> +#include <linux/swab.h>
> +#include <kvm/iodev.h>
> +#include <asm/csr.h>
> +#include <asm/kvm_aia_imsic.h>
> +
> +#define IMSIC_MAX_EIX (IMSIC_MAX_ID / BITS_PER_TYPE(u64))
> +
> +struct imsic_mrif_eix {
> + unsigned long eip[BITS_PER_TYPE(u64) / BITS_PER_LONG];
> + unsigned long eie[BITS_PER_TYPE(u64) / BITS_PER_LONG];
> +};
> +
> +struct imsic_mrif {
> + struct imsic_mrif_eix eix[IMSIC_MAX_EIX];
> + unsigned long eithreshold;
> + unsigned long eidelivery;
> +};
> +
> +struct imsic {
> + struct kvm_io_device iodev;
> +
> + u32 nr_msis;
> + u32 nr_eix;
> + u32 nr_hw_eix;
> +
> + /*
> + * At any point in time, the register state is in
> + * one of the following places:
> + *
> + * 1) Hardware: IMSIC VS-file (vsfile_cpu >= 0)
> + * 2) Software: IMSIC SW-file (vsfile_cpu < 0)
> + */
> +
> + /* IMSIC VS-file */
> + rwlock_t vsfile_lock;
> + int vsfile_cpu;
> + int vsfile_hgei;
> + void __iomem *vsfile_va;
> + phys_addr_t vsfile_pa;
> +
> + /* IMSIC SW-file */
> + struct imsic_mrif *swfile;
> + phys_addr_t swfile_pa;
> +};
> +
> +#define imsic_vs_csr_read(__c) \
> +({ \
> + unsigned long __r; \
> + csr_write(CSR_VSISELECT, __c); \
> + __r = csr_read(CSR_VSIREG); \
> + __r; \
> +})
> +
> +#define imsic_read_switchcase(__ireg) \
> + case __ireg: \
> + return imsic_vs_csr_read(__ireg);
> +#define imsic_read_switchcase_2(__ireg) \
> + imsic_read_switchcase(__ireg + 0) \
> + imsic_read_switchcase(__ireg + 1)
> +#define imsic_read_switchcase_4(__ireg) \
> + imsic_read_switchcase_2(__ireg + 0) \
> + imsic_read_switchcase_2(__ireg + 2)
> +#define imsic_read_switchcase_8(__ireg) \
> + imsic_read_switchcase_4(__ireg + 0) \
> + imsic_read_switchcase_4(__ireg + 4)
> +#define imsic_read_switchcase_16(__ireg) \
> + imsic_read_switchcase_8(__ireg + 0) \
> + imsic_read_switchcase_8(__ireg + 8)
> +#define imsic_read_switchcase_32(__ireg) \
> + imsic_read_switchcase_16(__ireg + 0) \
> + imsic_read_switchcase_16(__ireg + 16)
> +#define imsic_read_switchcase_64(__ireg) \
> + imsic_read_switchcase_32(__ireg + 0) \
> + imsic_read_switchcase_32(__ireg + 32)
> +
> +static unsigned long imsic_eix_read(int ireg)
> +{
> + switch (ireg) {
> + imsic_read_switchcase_64(IMSIC_EIP0)
> + imsic_read_switchcase_64(IMSIC_EIE0)
> + };
> +
> + return 0;
> +}
> +
> +#define imsic_vs_csr_swap(__c, __v) \
> +({ \
> + unsigned long __r; \
> + csr_write(CSR_VSISELECT, __c); \
> + __r = csr_swap(CSR_VSIREG, __v); \
> + __r; \
> +})
> +
> +#define imsic_swap_switchcase(__ireg, __v) \
> + case __ireg: \
> + return imsic_vs_csr_swap(__ireg, __v);
> +#define imsic_swap_switchcase_2(__ireg, __v) \
> + imsic_swap_switchcase(__ireg + 0, __v) \
> + imsic_swap_switchcase(__ireg + 1, __v)
> +#define imsic_swap_switchcase_4(__ireg, __v) \
> + imsic_swap_switchcase_2(__ireg + 0, __v) \
> + imsic_swap_switchcase_2(__ireg + 2, __v)
> +#define imsic_swap_switchcase_8(__ireg, __v) \
> + imsic_swap_switchcase_4(__ireg + 0, __v) \
> + imsic_swap_switchcase_4(__ireg + 4, __v)
> +#define imsic_swap_switchcase_16(__ireg, __v) \
> + imsic_swap_switchcase_8(__ireg + 0, __v) \
> + imsic_swap_switchcase_8(__ireg + 8, __v)
> +#define imsic_swap_switchcase_32(__ireg, __v) \
> + imsic_swap_switchcase_16(__ireg + 0, __v) \
> + imsic_swap_switchcase_16(__ireg + 16, __v)
> +#define imsic_swap_switchcase_64(__ireg, __v) \
> + imsic_swap_switchcase_32(__ireg + 0, __v) \
> + imsic_swap_switchcase_32(__ireg + 32, __v)
> +
> +static unsigned long imsic_eix_swap(int ireg, unsigned long val)
> +{
> + switch (ireg) {
> + imsic_swap_switchcase_64(IMSIC_EIP0, val)
> + imsic_swap_switchcase_64(IMSIC_EIE0, val)
> + };
> +
> + return 0;
> +}
> +
> +#define imsic_vs_csr_write(__c, __v) \
> +do { \
> + csr_write(CSR_VSISELECT, __c); \
> + csr_write(CSR_VSIREG, __v); \
> +} while (0)
> +
> +#define imsic_write_switchcase(__ireg, __v) \
> + case __ireg: \
> + imsic_vs_csr_write(__ireg, __v); \
> + break;
> +#define imsic_write_switchcase_2(__ireg, __v) \
> + imsic_write_switchcase(__ireg + 0, __v) \
> + imsic_write_switchcase(__ireg + 1, __v)
> +#define imsic_write_switchcase_4(__ireg, __v) \
> + imsic_write_switchcase_2(__ireg + 0, __v) \
> + imsic_write_switchcase_2(__ireg + 2, __v)
> +#define imsic_write_switchcase_8(__ireg, __v) \
> + imsic_write_switchcase_4(__ireg + 0, __v) \
> + imsic_write_switchcase_4(__ireg + 4, __v)
> +#define imsic_write_switchcase_16(__ireg, __v) \
> + imsic_write_switchcase_8(__ireg + 0, __v) \
> + imsic_write_switchcase_8(__ireg + 8, __v)
> +#define imsic_write_switchcase_32(__ireg, __v) \
> + imsic_write_switchcase_16(__ireg + 0, __v) \
> + imsic_write_switchcase_16(__ireg + 16, __v)
> +#define imsic_write_switchcase_64(__ireg, __v) \
> + imsic_write_switchcase_32(__ireg + 0, __v) \
> + imsic_write_switchcase_32(__ireg + 32, __v)
> +
> +static void imsic_eix_write(int ireg, unsigned long val)
> +{
> + switch (ireg) {
> + imsic_write_switchcase_64(IMSIC_EIP0, val)
> + imsic_write_switchcase_64(IMSIC_EIE0, val)
> + };
> +}
> +
> +#define imsic_vs_csr_set(__c, __v) \
> +do { \
> + csr_write(CSR_VSISELECT, __c); \
> + csr_set(CSR_VSIREG, __v); \
> +} while (0)
> +
> +#define imsic_set_switchcase(__ireg, __v) \
> + case __ireg: \
> + imsic_vs_csr_set(__ireg, __v); \
> + break;
> +#define imsic_set_switchcase_2(__ireg, __v) \
> + imsic_set_switchcase(__ireg + 0, __v) \
> + imsic_set_switchcase(__ireg + 1, __v)
> +#define imsic_set_switchcase_4(__ireg, __v) \
> + imsic_set_switchcase_2(__ireg + 0, __v) \
> + imsic_set_switchcase_2(__ireg + 2, __v)
> +#define imsic_set_switchcase_8(__ireg, __v) \
> + imsic_set_switchcase_4(__ireg + 0, __v) \
> + imsic_set_switchcase_4(__ireg + 4, __v)
> +#define imsic_set_switchcase_16(__ireg, __v) \
> + imsic_set_switchcase_8(__ireg + 0, __v) \
> + imsic_set_switchcase_8(__ireg + 8, __v)
> +#define imsic_set_switchcase_32(__ireg, __v) \
> + imsic_set_switchcase_16(__ireg + 0, __v) \
> + imsic_set_switchcase_16(__ireg + 16, __v)
> +#define imsic_set_switchcase_64(__ireg, __v) \
> + imsic_set_switchcase_32(__ireg + 0, __v) \
> + imsic_set_switchcase_32(__ireg + 32, __v)
> +
> +static void imsic_eix_set(int ireg, unsigned long val)
> +{
> + switch (ireg) {
> + imsic_set_switchcase_64(IMSIC_EIP0, val)
> + imsic_set_switchcase_64(IMSIC_EIE0, val)
> + };
> +}
> +
> +static unsigned long imsic_mrif_atomic_rmw(struct imsic_mrif *mrif,
> + unsigned long *ptr,
> + unsigned long new_val,
> + unsigned long wr_mask)
> +{
> + unsigned long old_val = 0, tmp = 0;
> +
> + __asm__ __volatile__ (
> + "0: lr.w.aq %1, %0\n"
> + " and %2, %1, %3\n"
> + " or %2, %2, %4\n"
> + " sc.w.rl %2, %2, %0\n"
> + " bnez %2, 0b"
> + : "+A" (*ptr), "+r" (old_val), "+r" (tmp)
> + : "r" (~wr_mask), "r" (new_val & wr_mask)
> + : "memory");
> +
> + return old_val;
> +}
> +
> +static unsigned long imsic_mrif_atomic_or(struct imsic_mrif *mrif,
> + unsigned long *ptr,
> + unsigned long val)
> +{
> + return arch_atomic_long_fetch_or(val, (atomic_long_t *)ptr);
> +}
> +
> +#define imsic_mrif_atomic_write(__mrif, __ptr, __new_val) \
> + imsic_mrif_atomic_rmw(__mrif, __ptr, __new_val, -1UL)
> +#define imsic_mrif_atomic_read(__mrif, __ptr) \
> + imsic_mrif_atomic_or(__mrif, __ptr, 0)
> +
> +static u32 imsic_mrif_topei(struct imsic_mrif *mrif, u32 nr_eix, u32 nr_msis)
> +{
> + struct imsic_mrif_eix *eix;
> + u32 i, imin, imax, ei, max_msi;
> + unsigned long eipend[BITS_PER_TYPE(u64) / BITS_PER_LONG];
> + unsigned long eithreshold = imsic_mrif_atomic_read(mrif,
> + &mrif->eithreshold);
> +
> + max_msi = (eithreshold && (eithreshold <= nr_msis)) ?
> + eithreshold : nr_msis;
> + for (ei = 0; ei < nr_eix; ei++) {
> + eix = &mrif->eix[ei];
> + eipend[0] = imsic_mrif_atomic_read(mrif, &eix->eie[0]) &
> + imsic_mrif_atomic_read(mrif, &eix->eip[0]);
> +#ifdef CONFIG_32BIT
> + eipend[1] = imsic_mrif_atomic_read(mrif, &eix->eie[1]) &
> + imsic_mrif_atomic_read(mrif, &eix->eip[1]);
> + if (!eipend[0] && !eipend[1])
> +#else
> + if (!eipend[0])
> +#endif
> + continue;
> +
> + imin = ei * BITS_PER_TYPE(u64);
> + imax = ((imin + BITS_PER_TYPE(u64)) < max_msi) ?
> + imin + BITS_PER_TYPE(u64) : max_msi;
> + for (i = (!imin) ? 1 : imin; i < imax; i++) {
> + if (test_bit(i - imin, eipend))
> + return (i << TOPEI_ID_SHIFT) | i;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int imsic_mrif_rmw(struct imsic_mrif *mrif, u32 nr_eix,
> + unsigned long isel, unsigned long *val,
> + unsigned long new_val, unsigned long wr_mask)
> +{
> + bool pend;
> + struct imsic_mrif_eix *eix;
> + unsigned long *ei, num, old_val = 0;
> +
> + switch (isel) {
> + case IMSIC_EIDELIVERY:
> + old_val = imsic_mrif_atomic_rmw(mrif, &mrif->eidelivery,
> + new_val, wr_mask & 0x1);
> + break;
> + case IMSIC_EITHRESHOLD:
> + old_val = imsic_mrif_atomic_rmw(mrif, &mrif->eithreshold,
> + new_val, wr_mask & (IMSIC_MAX_ID - 1));
> + break;
> + case IMSIC_EIP0 ... IMSIC_EIP63:
> + case IMSIC_EIE0 ... IMSIC_EIE63:
> + if (isel >= IMSIC_EIP0 && isel <= IMSIC_EIP63) {
> + pend = true;
> + num = isel - IMSIC_EIP0;
> + } else {
> + pend = false;
> + num = isel - IMSIC_EIE0;
> + }
> +
> + if ((num / 2) >= nr_eix)
> + return -EINVAL;
> + eix = &mrif->eix[num / 2];
> +
> +#ifndef CONFIG_32BIT
> + if (num & 0x1)
> + return -EINVAL;
> + ei = (pend) ? &eix->eip[0] : &eix->eie[0];
> +#else
> + ei = (pend) ? &eix->eip[num & 0x1] : &eix->eie[num & 0x1];
> +#endif
> +
> + /* Bit0 of EIP0 or EIE0 is read-only */
> + if (!num)
> + wr_mask &= ~BIT(0);
> +
> + old_val = imsic_mrif_atomic_rmw(mrif, ei, new_val, wr_mask);
> + break;
> + default:
> + return -ENOENT;
> + };
> +
> + if (val)
> + *val = old_val;
> +
> + return 0;
> +}
> +
> +struct imsic_vsfile_read_data {
> + int hgei;
> + u32 nr_eix;
> + bool clear;
> + struct imsic_mrif *mrif;
> +};
> +
> +static void imsic_vsfile_local_read(void *data)
> +{
> + u32 i;
> + struct imsic_mrif_eix *eix;
> + struct imsic_vsfile_read_data *idata = data;
> + struct imsic_mrif *mrif = idata->mrif;
> + unsigned long new_hstatus, old_hstatus, old_vsiselect;
> +
> + old_vsiselect = csr_read(CSR_VSISELECT);
> + old_hstatus = csr_read(CSR_HSTATUS);
> + new_hstatus = old_hstatus & ~HSTATUS_VGEIN;
> + new_hstatus |= ((unsigned long)idata->hgei) << HSTATUS_VGEIN_SHIFT;
> + csr_write(CSR_HSTATUS, new_hstatus);
> +
> + /*
> + * We don't use imsic_mrif_atomic_xyz() functions to store
> + * values in MRIF because imsic_vsfile_read() is always called
> + * with pointer to temporary MRIF on stack.
> + */
> +
> + if (idata->clear) {
> + mrif->eidelivery = imsic_vs_csr_swap(IMSIC_EIDELIVERY, 0);
> + mrif->eithreshold = imsic_vs_csr_swap(IMSIC_EITHRESHOLD, 0);
> + for (i = 0; i < idata->nr_eix; i++) {
> + eix = &mrif->eix[i];
> + eix->eip[0] = imsic_eix_swap(IMSIC_EIP0 + i * 2, 0);
> + eix->eie[0] = imsic_eix_swap(IMSIC_EIE0 + i * 2, 0);
> +#ifdef CONFIG_32BIT
> + eix->eip[1] = imsic_eix_swap(IMSIC_EIP0 + i * 2 + 1, 0);
> + eix->eie[1] = imsic_eix_swap(IMSIC_EIE0 + i * 2 + 1, 0);
> +#endif
> + }
> + } else {
> + mrif->eidelivery = imsic_vs_csr_read(IMSIC_EIDELIVERY);
> + mrif->eithreshold = imsic_vs_csr_read(IMSIC_EITHRESHOLD);
> + for (i = 0; i < idata->nr_eix; i++) {
> + eix = &mrif->eix[i];
> + eix->eip[0] = imsic_eix_read(IMSIC_EIP0 + i * 2);
> + eix->eie[0] = imsic_eix_read(IMSIC_EIE0 + i * 2);
> +#ifdef CONFIG_32BIT
> + eix->eip[1] = imsic_eix_read(IMSIC_EIP0 + i * 2 + 1);
> + eix->eie[1] = imsic_eix_read(IMSIC_EIE0 + i * 2 + 1);
> +#endif
> + }
> + }
> +
> + csr_write(CSR_HSTATUS, old_hstatus);
> + csr_write(CSR_VSISELECT, old_vsiselect);
> +}
> +
> +static void imsic_vsfile_read(int vsfile_hgei, int vsfile_cpu, u32 nr_eix,
> + bool clear, struct imsic_mrif *mrif)
> +{
> + struct imsic_vsfile_read_data idata;
> +
> + /* We can only read clear if we have a IMSIC VS-file */
> + if (vsfile_cpu < 0 || vsfile_hgei <= 0)
> + return;
> +
> + /* We can only read clear on local CPU */
> + idata.hgei = vsfile_hgei;
> + idata.nr_eix = nr_eix;
> + idata.clear = clear;
> + idata.mrif = mrif;
> + on_each_cpu_mask(cpumask_of(vsfile_cpu),
> + imsic_vsfile_local_read, &idata, 1);
> +}
> +
> +static void imsic_vsfile_local_clear(int vsfile_hgei, u32 nr_eix)
> +{
> + u32 i;
> + unsigned long new_hstatus, old_hstatus, old_vsiselect;
> +
> + /* We can only zero-out if we have a IMSIC VS-file */
> + if (vsfile_hgei <= 0)
> + return;
> +
> + old_vsiselect = csr_read(CSR_VSISELECT);
> + old_hstatus = csr_read(CSR_HSTATUS);
> + new_hstatus = old_hstatus & ~HSTATUS_VGEIN;
> + new_hstatus |= ((unsigned long)vsfile_hgei) << HSTATUS_VGEIN_SHIFT;
> + csr_write(CSR_HSTATUS, new_hstatus);
> +
> + imsic_vs_csr_write(IMSIC_EIDELIVERY, 0);
> + imsic_vs_csr_write(IMSIC_EITHRESHOLD, 0);
> + for (i = 0; i < nr_eix; i++) {
> + imsic_eix_write(IMSIC_EIP0 + i * 2, 0);
> + imsic_eix_write(IMSIC_EIE0 + i * 2, 0);
> +#ifdef CONFIG_32BIT
> + imsic_eix_write(IMSIC_EIP0 + i * 2 + 1, 0);
> + imsic_eix_write(IMSIC_EIE0 + i * 2 + 1, 0);
> +#endif
> + }
> +
> + csr_write(CSR_HSTATUS, old_hstatus);
> + csr_write(CSR_VSISELECT, old_vsiselect);
> +}
> +
> +static void imsic_vsfile_local_update(int vsfile_hgei, u32 nr_eix,
> + struct imsic_mrif *mrif)
> +{
> + u32 i;
> + struct imsic_mrif_eix *eix;
> + unsigned long new_hstatus, old_hstatus, old_vsiselect;
> +
> + /* We can only update if we have a HW IMSIC context */
> + if (vsfile_hgei <= 0)
> + return;
> +
> + /*
> + * We don't use imsic_mrif_atomic_xyz() functions to read values
> + * from MRIF in this function because it is always called with
> + * pointer to temporary MRIF on stack.
> + */
> +
> + old_vsiselect = csr_read(CSR_VSISELECT);
> + old_hstatus = csr_read(CSR_HSTATUS);
> + new_hstatus = old_hstatus & ~HSTATUS_VGEIN;
> + new_hstatus |= ((unsigned long)vsfile_hgei) << HSTATUS_VGEIN_SHIFT;
> + csr_write(CSR_HSTATUS, new_hstatus);
> +
> + for (i = 0; i < nr_eix; i++) {
> + eix = &mrif->eix[i];
> + imsic_eix_set(IMSIC_EIP0 + i * 2, eix->eip[0]);
> + imsic_eix_set(IMSIC_EIE0 + i * 2, eix->eie[0]);
> +#ifdef CONFIG_32BIT
> + imsic_eix_set(IMSIC_EIP0 + i * 2 + 1, eix->eip[1]);
> + imsic_eix_set(IMSIC_EIE0 + i * 2 + 1, eix->eie[1]);
> +#endif
> + }
> + imsic_vs_csr_write(IMSIC_EITHRESHOLD, mrif->eithreshold);
> + imsic_vs_csr_write(IMSIC_EIDELIVERY, mrif->eidelivery);
> +
> + csr_write(CSR_HSTATUS, old_hstatus);
> + csr_write(CSR_VSISELECT, old_vsiselect);
> +}
> +
> +static void imsic_vsfile_cleanup(struct imsic *imsic)
> +{
> + int old_vsfile_hgei, old_vsfile_cpu;
> + unsigned long flags;
> +
> + /*
> + * We don't use imsic_mrif_atomic_xyz() functions to clear the
> + * SW-file in this function because it is always called when the
> + * VCPU is being destroyed.
> + */
> +
> + write_lock_irqsave(&imsic->vsfile_lock, flags);
> + old_vsfile_hgei = imsic->vsfile_hgei;
> + old_vsfile_cpu = imsic->vsfile_cpu;
> + imsic->vsfile_cpu = imsic->vsfile_hgei = -1;
> + imsic->vsfile_va = NULL;
> + imsic->vsfile_pa = 0;
> + write_unlock_irqrestore(&imsic->vsfile_lock, flags);
> +
> + memset(imsic->swfile, 0, sizeof(*imsic->swfile));
> +
> + if (old_vsfile_cpu >= 0)
> + kvm_riscv_aia_free_hgei(old_vsfile_cpu, old_vsfile_hgei);
> +}
> +
> +static void imsic_swfile_extirq_update(struct kvm_vcpu *vcpu)
> +{
> + struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
> + struct imsic_mrif *mrif = imsic->swfile;
> +
> + if (imsic_mrif_atomic_read(mrif, &mrif->eidelivery) &&
> + imsic_mrif_topei(mrif, imsic->nr_eix, imsic->nr_msis))
> + kvm_riscv_vcpu_set_interrupt(vcpu, IRQ_VS_EXT);
> + else
> + kvm_riscv_vcpu_unset_interrupt(vcpu, IRQ_VS_EXT);
> +}
> +
> +static void imsic_swfile_read(struct kvm_vcpu *vcpu, bool clear,
> + struct imsic_mrif *mrif)
> +{
> + struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
> +
> + /*
> + * We don't use imsic_mrif_atomic_xyz() functions to read and
> + * write SW-file and MRIF in this function because it is always
> + * called when VCPU is not using SW-file and the MRIF points to
> + * a temporary MRIF on stack.
> + */
> +
> + memcpy(mrif, imsic->swfile, sizeof(*mrif));
> + if (clear) {
> + memset(imsic->swfile, 0, sizeof(*imsic->swfile));
> + kvm_riscv_vcpu_unset_interrupt(vcpu, IRQ_VS_EXT);
> + }
> +}
> +
> +static void imsic_swfile_update(struct kvm_vcpu *vcpu,
> + struct imsic_mrif *mrif)
> +{
> + u32 i;
> + struct imsic_mrif_eix *seix, *eix;
> + struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
> + struct imsic_mrif *smrif = imsic->swfile;
> +
> + imsic_mrif_atomic_write(smrif, &smrif->eidelivery, mrif->eidelivery);
> + imsic_mrif_atomic_write(smrif, &smrif->eithreshold, mrif->eithreshold);
> + for (i = 0; i < imsic->nr_eix; i++) {
> + seix = &smrif->eix[i];
> + eix = &mrif->eix[i];
> + imsic_mrif_atomic_or(smrif, &seix->eip[0], eix->eip[0]);
> + imsic_mrif_atomic_or(smrif, &seix->eie[0], eix->eie[0]);
> +#ifdef CONFIG_32BIT
> + imsic_mrif_atomic_or(smrif, &seix->eip[1], eix->eip[1]);
> + imsic_mrif_atomic_or(smrif, &seix->eie[1], eix->eie[1]);
> +#endif
> + }
> +
> + imsic_swfile_extirq_update(vcpu);
> +}
> +
> +void kvm_riscv_vcpu_aia_imsic_release(struct kvm_vcpu *vcpu)
> +{
> + unsigned long flags;
> + struct imsic_mrif tmrif;
> + int old_vsfile_hgei, old_vsfile_cpu;
> + struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
> +
> + /* Read and clear IMSIC VS-file details */
> + write_lock_irqsave(&imsic->vsfile_lock, flags);
> + old_vsfile_hgei = imsic->vsfile_hgei;
> + old_vsfile_cpu = imsic->vsfile_cpu;
> + imsic->vsfile_cpu = imsic->vsfile_hgei = -1;
> + imsic->vsfile_va = NULL;
> + imsic->vsfile_pa = 0;
> + write_unlock_irqrestore(&imsic->vsfile_lock, flags);
> +
> + /* Do nothing, if no IMSIC VS-file to release */
> + if (old_vsfile_cpu < 0)
> + return;
> +
> + /*
> + * At this point, all interrupt producers are still using
> + * the old IMSIC VS-file so we first re-direct all interrupt
> + * producers.
> + */
> +
> + /* Purge the G-stage mapping */
> + kvm_riscv_gstage_iounmap(vcpu->kvm,
> + vcpu->arch.aia_context.imsic_addr,
> + IMSIC_MMIO_PAGE_SZ);
> +
> + /* TODO: Purge the IOMMU mapping ??? */
> +
> + /*
> + * At this point, all interrupt producers have been re-directed
> + * to somewhere else so we move register state from the old IMSIC
> + * VS-file to the IMSIC SW-file.
> + */
> +
> + /* Read and clear register state from old IMSIC VS-file */
> + memset(&tmrif, 0, sizeof(tmrif));
> + imsic_vsfile_read(old_vsfile_hgei, old_vsfile_cpu, imsic->nr_hw_eix,
> + true, &tmrif);
> +
> + /* Update register state in IMSIC SW-file */
> + imsic_swfile_update(vcpu, &tmrif);
> +
> + /* Free-up old IMSIC VS-file */
> + kvm_riscv_aia_free_hgei(old_vsfile_cpu, old_vsfile_hgei);
> +}
> +
> +int kvm_riscv_vcpu_aia_imsic_update(struct kvm_vcpu *vcpu)
> +{
> + unsigned long flags;
> + phys_addr_t new_vsfile_pa;
> + struct imsic_mrif tmrif;
> + void __iomem *new_vsfile_va;
> + struct kvm *kvm = vcpu->kvm;
> + struct kvm_run *run = vcpu->run;
> + struct kvm_vcpu_aia *vaia = &vcpu->arch.aia_context;
> + struct imsic *imsic = vaia->imsic_state;
> + int ret = 0, new_vsfile_hgei = -1, old_vsfile_hgei, old_vsfile_cpu;
> +
> + /* Do nothing for emulation mode */
> + if (kvm->arch.aia.mode == KVM_DEV_RISCV_AIA_MODE_EMUL)
> + return 1;
> +
> + /* Read old IMSIC VS-file details */
> + read_lock_irqsave(&imsic->vsfile_lock, flags);
> + old_vsfile_hgei = imsic->vsfile_hgei;
> + old_vsfile_cpu = imsic->vsfile_cpu;
> + read_unlock_irqrestore(&imsic->vsfile_lock, flags);
> +
> + /* Do nothing if we are continuing on same CPU */
> + if (old_vsfile_cpu == vcpu->cpu)
> + return 1;
> +
> + /* Allocate new IMSIC VS-file */
> + ret = kvm_riscv_aia_alloc_hgei(vcpu->cpu, vcpu,
> + &new_vsfile_va, &new_vsfile_pa);
> + if (ret <= 0) {
> + /* For HW acceleration mode, we can't continue */
> + if (kvm->arch.aia.mode == KVM_DEV_RISCV_AIA_MODE_HWACCEL) {
> + run->fail_entry.hardware_entry_failure_reason =
> + CSR_HSTATUS;
> + run->fail_entry.cpu = vcpu->cpu;
> + run->exit_reason = KVM_EXIT_FAIL_ENTRY;
> + return 0;
> + }
> +
> + /* Release old IMSIC VS-file */
> + if (old_vsfile_cpu >= 0)
> + kvm_riscv_vcpu_aia_imsic_release(vcpu);
> +
> + /* For automatic mode, we continue */
> + goto done;
> + }
> + new_vsfile_hgei = ret;
> +
> + /*
> + * At this point, all interrupt producers are still using
> + * to the old IMSIC VS-file so we first move all interrupt
> + * producers to the new IMSIC VS-file.
> + */
> +
> + /* Zero-out new IMSIC VS-file */
> + imsic_vsfile_local_clear(new_vsfile_hgei, imsic->nr_hw_eix);
> +
> + /* Update G-stage mapping for the new IMSIC VS-file */
> + ret = kvm_riscv_gstage_ioremap(kvm, vcpu->arch.aia_context.imsic_addr,
> + new_vsfile_pa, IMSIC_MMIO_PAGE_SZ,
> + true, true);
> + if (ret)
> + goto fail_free_vsfile_hgei;
> +
> + /* TODO: Update the IOMMU mapping ??? */
> +
> + /* Update new IMSIC VS-file details in IMSIC context */
> + write_lock_irqsave(&imsic->vsfile_lock, flags);
> + imsic->vsfile_hgei = new_vsfile_hgei;
> + imsic->vsfile_cpu = vcpu->cpu;
> + imsic->vsfile_va = new_vsfile_va;
> + imsic->vsfile_pa = new_vsfile_pa;
> + write_unlock_irqrestore(&imsic->vsfile_lock, flags);
> +
> + /*
> + * At this point, all interrupt producers have been moved
> + * to the new IMSIC VS-file so we move register state from
> + * the old IMSIC VS/SW-file to the new IMSIC VS-file.
> + */
> +
> + memset(&tmrif, 0, sizeof(tmrif));
> + if (old_vsfile_cpu >= 0) {
> + /* Read and clear register state from old IMSIC VS-file */
> + imsic_vsfile_read(old_vsfile_hgei, old_vsfile_cpu,
> + imsic->nr_hw_eix, true, &tmrif);
> +
> + /* Free-up old IMSIC VS-file */
> + kvm_riscv_aia_free_hgei(old_vsfile_cpu, old_vsfile_hgei);
> + } else {
> + /* Read and clear register state from IMSIC SW-file */
> + imsic_swfile_read(vcpu, true, &tmrif);
> + }
> +
> + /* Restore register state in the new IMSIC VS-file */
> + imsic_vsfile_local_update(new_vsfile_hgei, imsic->nr_hw_eix, &tmrif);
> +
> +done:
> + /* Set VCPU HSTATUS.VGEIN to new IMSIC VS-file */
> + vcpu->arch.guest_context.hstatus &= ~HSTATUS_VGEIN;
> + if (new_vsfile_hgei > 0)
> + vcpu->arch.guest_context.hstatus |=
> + ((unsigned long)new_vsfile_hgei) << HSTATUS_VGEIN_SHIFT;
> +
> + /* Continue run-loop */
> + return 1;
> +
> +fail_free_vsfile_hgei:
> + kvm_riscv_aia_free_hgei(vcpu->cpu, new_vsfile_hgei);
> + return ret;
> +}
> +
> +int kvm_riscv_vcpu_aia_imsic_rmw(struct kvm_vcpu *vcpu, unsigned long isel,
> + unsigned long *val, unsigned long new_val,
> + unsigned long wr_mask)
> +{
> + u32 topei;
> + struct imsic_mrif_eix *eix;
> + int r, rc = KVM_INSN_CONTINUE_NEXT_SEPC;
> + struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
> +
> + if (isel == KVM_RISCV_AIA_IMSIC_TOPEI) {
> + /* Read pending and enabled interrupt with highest priority */
> + topei = imsic_mrif_topei(imsic->swfile, imsic->nr_eix,
> + imsic->nr_msis);
> + if (val)
> + *val = topei;
> +
> + /* Writes ignore value and clear top pending interrupt */
> + if (topei && wr_mask) {
> + topei >>= TOPEI_ID_SHIFT;
> + if (topei) {
> + eix = &imsic->swfile->eix[topei /
> + BITS_PER_TYPE(u64)];
> + clear_bit(topei & (BITS_PER_TYPE(u64) - 1),
> + eix->eip);
> + }
> + }
> + } else {
> + r = imsic_mrif_rmw(imsic->swfile, imsic->nr_eix, isel,
> + val, new_val, wr_mask);
> + /* Forward unknown IMSIC register to user-space */
> + if (r)
> + rc = (r == -ENOENT) ? 0 : KVM_INSN_ILLEGAL_TRAP;
> + }
> +
> + if (wr_mask)
> + imsic_swfile_extirq_update(vcpu);
> +
> + return rc;
> +}
> +
> +void kvm_riscv_vcpu_aia_imsic_reset(struct kvm_vcpu *vcpu)
> +{
> + struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
> +
> + if (!imsic)
> + return;
> +
> + kvm_riscv_vcpu_aia_imsic_release(vcpu);
> +
> + memset(imsic->swfile, 0, sizeof(*imsic->swfile));
> +}
> +
> +int kvm_riscv_vcpu_aia_imsic_inject(struct kvm_vcpu *vcpu,
> + u32 guest_index, u32 offset, u32 iid)
> +{
> + unsigned long flags;
> + struct imsic_mrif_eix *eix;
> + struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
> +
> + /* We only emulate one IMSIC MMIO page for each Guest VCPU */
> + if (!imsic || !iid || guest_index ||
> + (offset != IMSIC_MMIO_SETIPNUM_LE &&
> + offset != IMSIC_MMIO_SETIPNUM_BE))
> + return -ENODEV;
> +
> + iid = (offset == IMSIC_MMIO_SETIPNUM_BE) ? __swab32(iid) : iid;
> + if (imsic->nr_msis <= iid)
> + return -EINVAL;
> +
> + read_lock_irqsave(&imsic->vsfile_lock, flags);
> +
> + if (imsic->vsfile_cpu >= 0) {
> + writel(iid, imsic->vsfile_va + IMSIC_MMIO_SETIPNUM_LE);
> + kvm_vcpu_kick(vcpu);
> + } else {
> + eix = &imsic->swfile->eix[iid / BITS_PER_TYPE(u64)];
> + set_bit(iid & (BITS_PER_TYPE(u64) - 1), eix->eip);
> + imsic_swfile_extirq_update(vcpu);
> + }
> +
> + read_unlock_irqrestore(&imsic->vsfile_lock, flags);
> +
> + return 0;
> +}
> +
> +static int imsic_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
> + gpa_t addr, int len, void *val)
> +{
> + if (len != 4 || (addr & 0x3) != 0)
> + return -EOPNOTSUPP;
> +
> + *((u32 *)val) = 0;
> +
> + return 0;
> +}
> +
> +static int imsic_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
> + gpa_t addr, int len, const void *val)
> +{
> + struct kvm_msi msi = { 0 };
> +
> + if (len != 4 || (addr & 0x3) != 0)
> + return -EOPNOTSUPP;
> +
> + msi.address_hi = addr >> 32;
> + msi.address_lo = (u32)addr;
> + msi.data = *((const u32 *)val);
> + kvm_riscv_aia_inject_msi(vcpu->kvm, &msi);
> +
> + return 0;
> +};
> +
> +static struct kvm_io_device_ops imsic_iodoev_ops = {
> + .read = imsic_mmio_read,
> + .write = imsic_mmio_write,
> +};
> +
> +int kvm_riscv_vcpu_aia_imsic_init(struct kvm_vcpu *vcpu)
> +{
> + int ret = 0;
> + struct imsic *imsic;
> + struct page *swfile_page;
> + struct kvm *kvm = vcpu->kvm;
> +
> + /* Fail if we have zero IDs */
> + if (!kvm->arch.aia.nr_ids)
> + return -EINVAL;
> +
> + /* Allocate IMSIC context */
> + imsic = kzalloc(sizeof(*imsic), GFP_KERNEL);
> + if (!imsic)
> + return -ENOMEM;
> + vcpu->arch.aia_context.imsic_state = imsic;
> +
> + /* Setup IMSIC context */
> + imsic->nr_msis = kvm->arch.aia.nr_ids + 1;
> + rwlock_init(&imsic->vsfile_lock);
> + imsic->nr_eix = BITS_TO_U64(imsic->nr_msis);
> + imsic->nr_hw_eix = BITS_TO_U64(kvm_riscv_aia_max_ids);
> + imsic->vsfile_hgei = imsic->vsfile_cpu = -1;
> +
> + /* Setup IMSIC SW-file */
> + swfile_page = alloc_pages(GFP_KERNEL | __GFP_ZERO,
> + get_order(sizeof(*imsic->swfile)));
> + if (!swfile_page) {
> + ret = -ENOMEM;
> + goto fail_free_imsic;
> + }
> + imsic->swfile = page_to_virt(swfile_page);
> + imsic->swfile_pa = page_to_phys(swfile_page);
> +
> + /* Setup IO device */
> + kvm_iodevice_init(&imsic->iodev, &imsic_iodoev_ops);
> + mutex_lock(&kvm->slots_lock);
> + ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS,
> + vcpu->arch.aia_context.imsic_addr,
> + KVM_DEV_RISCV_IMSIC_SIZE,
> + &imsic->iodev);
> + mutex_unlock(&kvm->slots_lock);
> + if (ret)
> + goto fail_free_swfile;
> +
> + return 0;
> +
> +fail_free_swfile:
> + free_pages((unsigned long)imsic->swfile,
> + get_order(sizeof(*imsic->swfile)));
> +fail_free_imsic:
> + vcpu->arch.aia_context.imsic_state = NULL;
> + kfree(imsic);
> + return ret;
> +}
> +
> +void kvm_riscv_vcpu_aia_imsic_cleanup(struct kvm_vcpu *vcpu)
> +{
> + struct kvm *kvm = vcpu->kvm;
> + struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
> +
> + if (!imsic)
> + return;
> +
> + imsic_vsfile_cleanup(imsic);
> +
> + mutex_lock(&kvm->slots_lock);
> + kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &imsic->iodev);
> + mutex_unlock(&kvm->slots_lock);
> +
> + free_pages((unsigned long)imsic->swfile,
> + get_order(sizeof(*imsic->swfile)));
> +
> + vcpu->arch.aia_context.imsic_state = NULL;
> + kfree(imsic);
> +}
> --
> 2.34.1
>
Reviewed-by: Atish Patra <atishp@xxxxxxxxxxxx>
--
Regards,
Atish
