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 04/13] RISC-V: KVM: Break down the __kvm_riscv_switch_to() into macros
Date: Mon, 21 Oct 2024 01:17:25 +0530 [thread overview]
Message-ID: <20241020194734.58686-5-apatel@ventanamicro.com> (raw)
In-Reply-To: <20241020194734.58686-1-apatel@ventanamicro.com>
Break down the __kvm_riscv_switch_to() function into macros so that
these macros can be later re-used by SBI NACL extension based low-level
switch function.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
---
arch/riscv/kvm/vcpu_switch.S | 52 +++++++++++++++++++++++++++---------
1 file changed, 40 insertions(+), 12 deletions(-)
diff --git a/arch/riscv/kvm/vcpu_switch.S b/arch/riscv/kvm/vcpu_switch.S
index 3f8cbc21a644..9f13e5ce6a18 100644
--- a/arch/riscv/kvm/vcpu_switch.S
+++ b/arch/riscv/kvm/vcpu_switch.S
@@ -11,11 +11,7 @@
#include <asm/asm-offsets.h>
#include <asm/csr.h>
- .text
- .altmacro
- .option norelax
-
-SYM_FUNC_START(__kvm_riscv_switch_to)
+.macro SAVE_HOST_GPRS
/* Save Host GPRs (except A0 and T0-T6) */
REG_S ra, (KVM_ARCH_HOST_RA)(a0)
REG_S sp, (KVM_ARCH_HOST_SP)(a0)
@@ -40,10 +36,12 @@ SYM_FUNC_START(__kvm_riscv_switch_to)
REG_S s9, (KVM_ARCH_HOST_S9)(a0)
REG_S s10, (KVM_ARCH_HOST_S10)(a0)
REG_S s11, (KVM_ARCH_HOST_S11)(a0)
+.endm
+.macro SAVE_HOST_AND_RESTORE_GUEST_CSRS __resume_addr
/* Load Guest CSR values */
REG_L t0, (KVM_ARCH_GUEST_SSTATUS)(a0)
- la t1, .Lkvm_switch_return
+ la t1, \__resume_addr
REG_L t2, (KVM_ARCH_GUEST_SEPC)(a0)
/* Save Host and Restore Guest SSTATUS */
@@ -62,7 +60,9 @@ SYM_FUNC_START(__kvm_riscv_switch_to)
REG_S t0, (KVM_ARCH_HOST_SSTATUS)(a0)
REG_S t1, (KVM_ARCH_HOST_STVEC)(a0)
REG_S t3, (KVM_ARCH_HOST_SSCRATCH)(a0)
+.endm
+.macro RESTORE_GUEST_GPRS
/* Restore Guest GPRs (except A0) */
REG_L ra, (KVM_ARCH_GUEST_RA)(a0)
REG_L sp, (KVM_ARCH_GUEST_SP)(a0)
@@ -97,13 +97,9 @@ SYM_FUNC_START(__kvm_riscv_switch_to)
/* Restore Guest A0 */
REG_L a0, (KVM_ARCH_GUEST_A0)(a0)
+.endm
- /* Resume Guest */
- sret
-
- /* Back to Host */
- .align 2
-.Lkvm_switch_return:
+.macro SAVE_GUEST_GPRS
/* Swap Guest A0 with SSCRATCH */
csrrw a0, CSR_SSCRATCH, a0
@@ -138,7 +134,9 @@ SYM_FUNC_START(__kvm_riscv_switch_to)
REG_S t4, (KVM_ARCH_GUEST_T4)(a0)
REG_S t5, (KVM_ARCH_GUEST_T5)(a0)
REG_S t6, (KVM_ARCH_GUEST_T6)(a0)
+.endm
+.macro SAVE_GUEST_AND_RESTORE_HOST_CSRS
/* Load Host CSR values */
REG_L t0, (KVM_ARCH_HOST_STVEC)(a0)
REG_L t1, (KVM_ARCH_HOST_SSCRATCH)(a0)
@@ -160,7 +158,9 @@ SYM_FUNC_START(__kvm_riscv_switch_to)
REG_S t1, (KVM_ARCH_GUEST_A0)(a0)
REG_S t2, (KVM_ARCH_GUEST_SSTATUS)(a0)
REG_S t3, (KVM_ARCH_GUEST_SEPC)(a0)
+.endm
+.macro RESTORE_HOST_GPRS
/* Restore Host GPRs (except A0 and T0-T6) */
REG_L ra, (KVM_ARCH_HOST_RA)(a0)
REG_L sp, (KVM_ARCH_HOST_SP)(a0)
@@ -185,6 +185,34 @@ SYM_FUNC_START(__kvm_riscv_switch_to)
REG_L s9, (KVM_ARCH_HOST_S9)(a0)
REG_L s10, (KVM_ARCH_HOST_S10)(a0)
REG_L s11, (KVM_ARCH_HOST_S11)(a0)
+.endm
+
+ .text
+ .altmacro
+ .option norelax
+
+ /*
+ * Parameters:
+ * A0 <= Pointer to struct kvm_vcpu_arch
+ */
+SYM_FUNC_START(__kvm_riscv_switch_to)
+ SAVE_HOST_GPRS
+
+ SAVE_HOST_AND_RESTORE_GUEST_CSRS .Lkvm_switch_return
+
+ RESTORE_GUEST_GPRS
+
+ /* Resume Guest using SRET */
+ sret
+
+ /* Back to Host */
+ .align 2
+.Lkvm_switch_return:
+ SAVE_GUEST_GPRS
+
+ SAVE_GUEST_AND_RESTORE_HOST_CSRS
+
+ RESTORE_HOST_GPRS
/* Return to C code */
ret
--
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 ` [PATCH v2 03/13] RISC-V: KVM: Save/restore SCOUNTEREN " Anup Patel
2024-10-20 19:47 ` Anup Patel [this message]
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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