From: Anup Patel <apatel@ventanamicro.com>
To: Palmer Dabbelt <palmer@dabbelt.com>,
Paul Walmsley <paul.walmsley@sifive.com>
Cc: Atish Patra <atishp@atishpatra.org>,
Andrew Jones <ajones@ventanamicro.com>,
Anup Patel <anup@brainfault.org>,
kvm@vger.kernel.org, kvm-riscv@lists.infradead.org,
linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
Anup Patel <apatel@ventanamicro.com>,
Atish Patra <atishp@rivosinc.com>
Subject: [PATCH v2 03/13] RISC-V: KVM: Save/restore SCOUNTEREN in C source
Date: Mon, 21 Oct 2024 01:17:24 +0530 [thread overview]
Message-ID: <20241020194734.58686-4-apatel@ventanamicro.com> (raw)
In-Reply-To: <20241020194734.58686-1-apatel@ventanamicro.com>
The SCOUNTEREN CSR need not be saved/restored in the low-level
__kvm_riscv_switch_to() function hence move the SCOUNTEREN CSR
save/restore to the kvm_riscv_vcpu_swap_in_guest_state() and
kvm_riscv_vcpu_swap_in_host_state() functions in C sources.
Also, re-arrange the CSR save/restore and related GPR usage in
the low-level __kvm_riscv_switch_to() low-level function.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
---
arch/riscv/kvm/vcpu.c | 2 ++
arch/riscv/kvm/vcpu_switch.S | 52 +++++++++++++++---------------------
2 files changed, 23 insertions(+), 31 deletions(-)
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index 53ee29490c7f..a972dd46e7e4 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -702,6 +702,7 @@ static __always_inline void kvm_riscv_vcpu_swap_in_guest_state(struct kvm_vcpu *
struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
struct kvm_vcpu_config *cfg = &vcpu->arch.cfg;
+ vcpu->arch.host_scounteren = csr_swap(CSR_SCOUNTEREN, csr->scounteren);
vcpu->arch.host_senvcfg = csr_swap(CSR_SENVCFG, csr->senvcfg);
if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN) &&
(cfg->hstateen0 & SMSTATEEN0_SSTATEEN0))
@@ -715,6 +716,7 @@ static __always_inline void kvm_riscv_vcpu_swap_in_host_state(struct kvm_vcpu *v
struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
struct kvm_vcpu_config *cfg = &vcpu->arch.cfg;
+ csr->scounteren = csr_swap(CSR_SCOUNTEREN, vcpu->arch.host_scounteren);
csr->senvcfg = csr_swap(CSR_SENVCFG, vcpu->arch.host_senvcfg);
if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN) &&
(cfg->hstateen0 & SMSTATEEN0_SSTATEEN0))
diff --git a/arch/riscv/kvm/vcpu_switch.S b/arch/riscv/kvm/vcpu_switch.S
index f83643c4fdb9..3f8cbc21a644 100644
--- a/arch/riscv/kvm/vcpu_switch.S
+++ b/arch/riscv/kvm/vcpu_switch.S
@@ -43,30 +43,25 @@ SYM_FUNC_START(__kvm_riscv_switch_to)
/* Load Guest CSR values */
REG_L t0, (KVM_ARCH_GUEST_SSTATUS)(a0)
- REG_L t1, (KVM_ARCH_GUEST_SCOUNTEREN)(a0)
- la t3, .Lkvm_switch_return
- REG_L t4, (KVM_ARCH_GUEST_SEPC)(a0)
+ la t1, .Lkvm_switch_return
+ REG_L t2, (KVM_ARCH_GUEST_SEPC)(a0)
/* Save Host and Restore Guest SSTATUS */
csrrw t0, CSR_SSTATUS, t0
- /* Save Host and Restore Guest SCOUNTEREN */
- csrrw t1, CSR_SCOUNTEREN, t1
-
/* Save Host STVEC and change it to return path */
- csrrw t3, CSR_STVEC, t3
-
- /* Save Host SSCRATCH and change it to struct kvm_vcpu_arch pointer */
- csrrw t2, CSR_SSCRATCH, a0
+ csrrw t1, CSR_STVEC, t1
/* Restore Guest SEPC */
- csrw CSR_SEPC, t4
+ csrw CSR_SEPC, t2
+
+ /* Save Host SSCRATCH and change it to struct kvm_vcpu_arch pointer */
+ csrrw t3, CSR_SSCRATCH, a0
/* Store Host CSR values */
REG_S t0, (KVM_ARCH_HOST_SSTATUS)(a0)
- REG_S t1, (KVM_ARCH_HOST_SCOUNTEREN)(a0)
- REG_S t2, (KVM_ARCH_HOST_SSCRATCH)(a0)
- REG_S t3, (KVM_ARCH_HOST_STVEC)(a0)
+ REG_S t1, (KVM_ARCH_HOST_STVEC)(a0)
+ REG_S t3, (KVM_ARCH_HOST_SSCRATCH)(a0)
/* Restore Guest GPRs (except A0) */
REG_L ra, (KVM_ARCH_GUEST_RA)(a0)
@@ -145,31 +140,26 @@ SYM_FUNC_START(__kvm_riscv_switch_to)
REG_S t6, (KVM_ARCH_GUEST_T6)(a0)
/* Load Host CSR values */
- REG_L t1, (KVM_ARCH_HOST_STVEC)(a0)
- REG_L t2, (KVM_ARCH_HOST_SSCRATCH)(a0)
- REG_L t3, (KVM_ARCH_HOST_SCOUNTEREN)(a0)
- REG_L t4, (KVM_ARCH_HOST_SSTATUS)(a0)
-
- /* Save Guest SEPC */
- csrr t0, CSR_SEPC
+ REG_L t0, (KVM_ARCH_HOST_STVEC)(a0)
+ REG_L t1, (KVM_ARCH_HOST_SSCRATCH)(a0)
+ REG_L t2, (KVM_ARCH_HOST_SSTATUS)(a0)
/* Save Guest A0 and Restore Host SSCRATCH */
- csrrw t2, CSR_SSCRATCH, t2
+ csrrw t1, CSR_SSCRATCH, t1
- /* Restore Host STVEC */
- csrw CSR_STVEC, t1
+ /* Save Guest SEPC */
+ csrr t3, CSR_SEPC
- /* Save Guest and Restore Host SCOUNTEREN */
- csrrw t3, CSR_SCOUNTEREN, t3
+ /* Restore Host STVEC */
+ csrw CSR_STVEC, t0
/* Save Guest and Restore Host SSTATUS */
- csrrw t4, CSR_SSTATUS, t4
+ csrrw t2, CSR_SSTATUS, t2
/* Store Guest CSR values */
- REG_S t0, (KVM_ARCH_GUEST_SEPC)(a0)
- REG_S t2, (KVM_ARCH_GUEST_A0)(a0)
- REG_S t3, (KVM_ARCH_GUEST_SCOUNTEREN)(a0)
- REG_S t4, (KVM_ARCH_GUEST_SSTATUS)(a0)
+ REG_S t1, (KVM_ARCH_GUEST_A0)(a0)
+ REG_S t2, (KVM_ARCH_GUEST_SSTATUS)(a0)
+ REG_S t3, (KVM_ARCH_GUEST_SEPC)(a0)
/* Restore Host GPRs (except A0 and T0-T6) */
REG_L ra, (KVM_ARCH_HOST_RA)(a0)
--
2.43.0
next prev parent reply other threads:[~2024-10-20 19:47 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-20 19:47 [PATCH v2 00/13] Accelerate KVM RISC-V when running as a guest Anup Patel
2024-10-20 19:47 ` [PATCH v2 01/13] RISC-V: KVM: Order the object files alphabetically Anup Patel
2024-10-20 19:47 ` [PATCH v2 02/13] RISC-V: KVM: Save/restore HSTATUS in C source Anup Patel
2024-10-20 19:47 ` Anup Patel [this message]
2024-10-20 19:47 ` [PATCH v2 04/13] RISC-V: KVM: Break down the __kvm_riscv_switch_to() into macros Anup Patel
2024-10-20 19:47 ` [PATCH v2 05/13] RISC-V: KVM: Replace aia_set_hvictl() with aia_hvictl_value() Anup Patel
2024-10-20 19:47 ` [PATCH v2 06/13] RISC-V: KVM: Don't setup SGEI for zero guest external interrupts Anup Patel
2024-10-20 19:47 ` [PATCH v2 07/13] RISC-V: Add defines for the SBI nested acceleration extension Anup Patel
2024-10-20 19:47 ` [PATCH v2 08/13] RISC-V: KVM: Add common nested acceleration support Anup Patel
2024-10-20 19:47 ` [PATCH v2 09/13] RISC-V: KVM: Use nacl_csr_xyz() for accessing H-extension CSRs Anup Patel
2024-10-20 19:47 ` [PATCH v2 10/13] RISC-V: KVM: Use nacl_csr_xyz() for accessing AIA CSRs Anup Patel
2024-10-20 19:47 ` [PATCH v2 11/13] RISC-V: KVM: Use SBI sync SRET call when available Anup Patel
2024-10-20 19:47 ` [PATCH v2 12/13] RISC-V: KVM: Save trap CSRs in kvm_riscv_vcpu_enter_exit() Anup Patel
2024-10-20 19:47 ` [PATCH v2 13/13] RISC-V: KVM: Use NACL HFENCEs for KVM request based HFENCEs Anup Patel
2024-10-24 23:56 ` Atish Patra
2024-10-25 16:57 ` [PATCH v2 00/13] Accelerate KVM RISC-V when running as a guest Anup Patel
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