[v1,16/36] target/riscv: Add virtual register swapping function
diff mbox series

Message ID e89e42f47b337c82ff7fe0ef50986e2df0d7214a.1575914822.git.alistair.francis@wdc.com
State New
Headers show
Series
  • Add RISC-V Hypervisor Extension v0.5
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Commit Message

Alistair Francis Dec. 9, 2019, 6:11 p.m. UTC
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.h        | 10 +++++++
 target/riscv/cpu_bits.h   |  7 +++++
 target/riscv/cpu_helper.c | 63 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 80 insertions(+)

Comments

Palmer Dabbelt Jan. 8, 2020, 2:07 a.m. UTC | #1
On Mon, 09 Dec 2019 10:11:22 PST (-0800), Alistair Francis wrote:
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/cpu.h        | 10 +++++++
>  target/riscv/cpu_bits.h   |  7 +++++
>  target/riscv/cpu_helper.c | 63 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 80 insertions(+)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 9dc8303c62..eb089fbdb6 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -125,6 +125,7 @@ struct CPURISCVState {
>      target_ulong *mstatus;
>
>      target_ulong mip;
> +
>      uint32_t miclaim;
>
>      target_ulong mie;
> @@ -173,6 +174,14 @@ struct CPURISCVState {
>      target_ulong mtval2;
>      target_ulong mtinst;
>
> +    /* HS Backup CSRs */
> +    target_ulong stvec_hs;
> +    target_ulong sscratch_hs;
> +    target_ulong sepc_hs;
> +    target_ulong scause_hs;
> +    target_ulong stval_hs;
> +    target_ulong satp_hs;
> +
>      target_ulong scounteren;
>      target_ulong mcounteren;
>
> @@ -303,6 +312,7 @@ void riscv_cpu_list(void);
>  #define cpu_mmu_index riscv_cpu_mmu_index
>
>  #ifndef CONFIG_USER_ONLY
> +void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env);
>  int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts);
>  uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value);
>  #define BOOL_TO_MASK(x) (-!!(x)) /* helper for riscv_cpu_update_mip value */
> diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
> index ad6479796c..a24654d137 100644
> --- a/target/riscv/cpu_bits.h
> +++ b/target/riscv/cpu_bits.h
> @@ -553,4 +553,11 @@
>  #define SIP_STIP                           MIP_STIP
>  #define SIP_SEIP                           MIP_SEIP
>
> +/* MIE masks */
> +#define MIE_SEIE                           (1 << IRQ_S_EXT)
> +#define MIE_UEIE                           (1 << IRQ_U_EXT)
> +#define MIE_STIE                           (1 << IRQ_S_TIMER)
> +#define MIE_UTIE                           (1 << IRQ_U_TIMER)
> +#define MIE_SSIE                           (1 << IRQ_S_SOFT)
> +#define MIE_USIE                           (1 << IRQ_U_SOFT)
>  #endif
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 9684da7f7d..63439c9370 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -82,6 +82,69 @@ bool riscv_cpu_fp_enabled(CPURISCVState *env)
>      return false;
>  }
>
> +void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
> +{
> +    target_ulong mstatus_mask = MSTATUS_MXR | MSTATUS_SUM | MSTATUS_FS |
> +                                MSTATUS_SPP | MSTATUS_SPIE | MSTATUS_SIE;
> +    bool current_virt = riscv_cpu_virt_enabled(env);
> +
> +    g_assert(riscv_has_ext(env, RVH));
> +
> +#if defined(TARGET_RISCV64)
> +    mstatus_mask |= MSTATUS64_UXL;
> +#endif
> +
> +    if (current_virt) {
> +        /* Current V=1 and we are about to change to V=0 */
> +        env->mstatus = &env->mstatus_novirt;
> +        *env->mstatus &= mstatus_mask;
> +        *env->mstatus |= env->vsstatus & ~mstatus_mask;
> +        /* Ensure that vsstatus only holds the correct bits */
> +        env->vsstatus &= mstatus_mask;
> +
> +        env->vstvec = env->stvec;
> +        env->stvec = env->stvec_hs;
> +
> +        env->vsscratch = env->sscratch;
> +        env->sscratch = env->sscratch_hs;
> +
> +        env->vsepc = env->sepc;
> +        env->sepc = env->sepc_hs;
> +
> +        env->vscause = env->scause;
> +        env->scause = env->scause_hs;
> +
> +        env->vstval = env->sbadaddr;
> +        env->sbadaddr = env->stval_hs;
> +
> +        env->vsatp = env->satp;
> +        env->satp = env->satp_hs;
> +    } else {
> +        /* Current V=0 and we are about to change to V=1 */
> +        env->mstatus = &env->vsstatus;
> +        *env->mstatus &= mstatus_mask;
> +        *env->mstatus |= env->mstatus_novirt & ~mstatus_mask;
> +
> +        env->stvec_hs = env->stvec;
> +        env->stvec = env->vstvec;
> +
> +        env->sscratch_hs = env->sscratch;
> +        env->sscratch = env->vsscratch;
> +
> +        env->sepc_hs = env->sepc;
> +        env->sepc = env->vsepc;
> +
> +        env->scause_hs = env->scause;
> +        env->scause = env->vscause;
> +
> +        env->stval_hs = env->sbadaddr;
> +        env->sbadaddr = env->vstval;
> +
> +        env->satp_hs = env->satp;
> +        env->satp = env->vsatp;
> +    }
> +}
> +
>  bool riscv_cpu_virt_enabled(CPURISCVState *env)
>  {
>      if (!riscv_has_ext(env, RVH)) {

Modulo that question about the concept of pointer swapping on the previous
patch:

Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>

Patch
diff mbox series

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 9dc8303c62..eb089fbdb6 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -125,6 +125,7 @@  struct CPURISCVState {
     target_ulong *mstatus;
 
     target_ulong mip;
+
     uint32_t miclaim;
 
     target_ulong mie;
@@ -173,6 +174,14 @@  struct CPURISCVState {
     target_ulong mtval2;
     target_ulong mtinst;
 
+    /* HS Backup CSRs */
+    target_ulong stvec_hs;
+    target_ulong sscratch_hs;
+    target_ulong sepc_hs;
+    target_ulong scause_hs;
+    target_ulong stval_hs;
+    target_ulong satp_hs;
+
     target_ulong scounteren;
     target_ulong mcounteren;
 
@@ -303,6 +312,7 @@  void riscv_cpu_list(void);
 #define cpu_mmu_index riscv_cpu_mmu_index
 
 #ifndef CONFIG_USER_ONLY
+void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env);
 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts);
 uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value);
 #define BOOL_TO_MASK(x) (-!!(x)) /* helper for riscv_cpu_update_mip value */
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index ad6479796c..a24654d137 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -553,4 +553,11 @@ 
 #define SIP_STIP                           MIP_STIP
 #define SIP_SEIP                           MIP_SEIP
 
+/* MIE masks */
+#define MIE_SEIE                           (1 << IRQ_S_EXT)
+#define MIE_UEIE                           (1 << IRQ_U_EXT)
+#define MIE_STIE                           (1 << IRQ_S_TIMER)
+#define MIE_UTIE                           (1 << IRQ_U_TIMER)
+#define MIE_SSIE                           (1 << IRQ_S_SOFT)
+#define MIE_USIE                           (1 << IRQ_U_SOFT)
 #endif
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 9684da7f7d..63439c9370 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -82,6 +82,69 @@  bool riscv_cpu_fp_enabled(CPURISCVState *env)
     return false;
 }
 
+void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
+{
+    target_ulong mstatus_mask = MSTATUS_MXR | MSTATUS_SUM | MSTATUS_FS |
+                                MSTATUS_SPP | MSTATUS_SPIE | MSTATUS_SIE;
+    bool current_virt = riscv_cpu_virt_enabled(env);
+
+    g_assert(riscv_has_ext(env, RVH));
+
+#if defined(TARGET_RISCV64)
+    mstatus_mask |= MSTATUS64_UXL;
+#endif
+
+    if (current_virt) {
+        /* Current V=1 and we are about to change to V=0 */
+        env->mstatus = &env->mstatus_novirt;
+        *env->mstatus &= mstatus_mask;
+        *env->mstatus |= env->vsstatus & ~mstatus_mask;
+        /* Ensure that vsstatus only holds the correct bits */
+        env->vsstatus &= mstatus_mask;
+
+        env->vstvec = env->stvec;
+        env->stvec = env->stvec_hs;
+
+        env->vsscratch = env->sscratch;
+        env->sscratch = env->sscratch_hs;
+
+        env->vsepc = env->sepc;
+        env->sepc = env->sepc_hs;
+
+        env->vscause = env->scause;
+        env->scause = env->scause_hs;
+
+        env->vstval = env->sbadaddr;
+        env->sbadaddr = env->stval_hs;
+
+        env->vsatp = env->satp;
+        env->satp = env->satp_hs;
+    } else {
+        /* Current V=0 and we are about to change to V=1 */
+        env->mstatus = &env->vsstatus;
+        *env->mstatus &= mstatus_mask;
+        *env->mstatus |= env->mstatus_novirt & ~mstatus_mask;
+
+        env->stvec_hs = env->stvec;
+        env->stvec = env->vstvec;
+
+        env->sscratch_hs = env->sscratch;
+        env->sscratch = env->vsscratch;
+
+        env->sepc_hs = env->sepc;
+        env->sepc = env->vsepc;
+
+        env->scause_hs = env->scause;
+        env->scause = env->vscause;
+
+        env->stval_hs = env->sbadaddr;
+        env->sbadaddr = env->vstval;
+
+        env->satp_hs = env->satp;
+        env->satp = env->vsatp;
+    }
+}
+
 bool riscv_cpu_virt_enabled(CPURISCVState *env)
 {
     if (!riscv_has_ext(env, RVH)) {