[PATCH v3 09/10] RISC-V: KVM: Add in-kernel virtualization of AIA IMSIC

Anup Patel
2023-06-15T07:35:57Z

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@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
---
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@ventanamicro.com>
+ */
+
+#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