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KVM: MIPS: clean up redundant kvm_run parameters in assembly
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In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu'
structure. For historical reasons, many kvm-related function parameters
retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time. This
patch does a unified cleanup of these remaining redundant parameters.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: Huacai Chen <chenhc@lemote.com>
Tested-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Message-Id: <20200623131418.31473-6-tianjia.zhang@linux.alibaba.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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uudiin authored and bonzini committed Sep 28, 2020
1 parent 95b28ac commit 0b7aa58
Showing 5 changed files with 14 additions and 18 deletions.
4 changes: 2 additions & 2 deletions arch/mips/include/asm/kvm_host.h
Original file line number Diff line number Diff line change
@@ -341,7 +341,7 @@ struct kvm_mips_tlb {
#define KVM_MIPS_GUEST_TLB_SIZE 64
struct kvm_vcpu_arch {
void *guest_ebase;
int (*vcpu_run)(struct kvm_run *run, struct kvm_vcpu *vcpu);
int (*vcpu_run)(struct kvm_vcpu *vcpu);

/* Host registers preserved across guest mode execution */
unsigned long host_stack;
@@ -852,7 +852,7 @@ int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks);
/* Debug: dump vcpu state */
int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu);

extern int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu);
extern int kvm_mips_handle_exit(struct kvm_vcpu *vcpu);

/* Building of entry/exception code */
int kvm_mips_entry_setup(void);
21 changes: 8 additions & 13 deletions arch/mips/kvm/entry.c
Original file line number Diff line number Diff line change
@@ -205,7 +205,7 @@ static inline void build_set_exc_base(u32 **p, unsigned int reg)
* Assemble the start of the vcpu_run function to run a guest VCPU. The function
* conforms to the following prototype:
*
* int vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu);
* int vcpu_run(struct kvm_vcpu *vcpu);
*
* The exit from the guest and return to the caller is handled by the code
* generated by kvm_mips_build_ret_to_host().
@@ -218,8 +218,7 @@ void *kvm_mips_build_vcpu_run(void *addr)
unsigned int i;

/*
* A0: run
* A1: vcpu
* A0: vcpu
*/

/* k0/k1 not being used in host kernel context */
@@ -238,10 +237,10 @@ void *kvm_mips_build_vcpu_run(void *addr)
kvm_mips_build_save_scratch(&p, V1, K1);

/* VCPU scratch register has pointer to vcpu */
UASM_i_MTC0(&p, A1, scratch_vcpu[0], scratch_vcpu[1]);
UASM_i_MTC0(&p, A0, scratch_vcpu[0], scratch_vcpu[1]);

/* Offset into vcpu->arch */
UASM_i_ADDIU(&p, K1, A1, offsetof(struct kvm_vcpu, arch));
UASM_i_ADDIU(&p, K1, A0, offsetof(struct kvm_vcpu, arch));

/*
* Save the host stack to VCPU, used for exception processing
@@ -645,10 +644,7 @@ void *kvm_mips_build_exit(void *addr)
/* Now that context has been saved, we can use other registers */

/* Restore vcpu */
UASM_i_MFC0(&p, S1, scratch_vcpu[0], scratch_vcpu[1]);

/* Restore run (vcpu->run) */
UASM_i_LW(&p, S0, offsetof(struct kvm_vcpu, run), S1);
UASM_i_MFC0(&p, S0, scratch_vcpu[0], scratch_vcpu[1]);

/*
* Save Host level EPC, BadVaddr and Cause to VCPU, useful to process
@@ -810,7 +806,6 @@ void *kvm_mips_build_exit(void *addr)
* with this in the kernel
*/
uasm_i_move(&p, A0, S0);
uasm_i_move(&p, A1, S1);
UASM_i_LA(&p, T9, (unsigned long)kvm_mips_handle_exit);
uasm_i_jalr(&p, RA, T9);
UASM_i_ADDIU(&p, SP, SP, -CALLFRAME_SIZ);
@@ -852,7 +847,7 @@ static void *kvm_mips_build_ret_from_exit(void *addr)
* guest, reload k1
*/

uasm_i_move(&p, K1, S1);
uasm_i_move(&p, K1, S0);
UASM_i_ADDIU(&p, K1, K1, offsetof(struct kvm_vcpu, arch));

/*
@@ -886,8 +881,8 @@ static void *kvm_mips_build_ret_to_guest(void *addr)
{
u32 *p = addr;

/* Put the saved pointer to vcpu (s1) back into the scratch register */
UASM_i_MTC0(&p, S1, scratch_vcpu[0], scratch_vcpu[1]);
/* Put the saved pointer to vcpu (s0) back into the scratch register */
UASM_i_MTC0(&p, S0, scratch_vcpu[0], scratch_vcpu[1]);

/* Load up the Guest EBASE to minimize the window where BEV is set */
UASM_i_LW(&p, T0, offsetof(struct kvm_vcpu_arch, guest_ebase), K1);
3 changes: 2 additions & 1 deletion arch/mips/kvm/mips.c
Original file line number Diff line number Diff line change
@@ -1199,8 +1199,9 @@ static void kvm_mips_set_c0_status(void)
/*
* Return value is in the form (errcode<<2 | RESUME_FLAG_HOST | RESUME_FLAG_NV)
*/
int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
int kvm_mips_handle_exit(struct kvm_vcpu *vcpu)
{
struct kvm_run *run = vcpu->run;
u32 cause = vcpu->arch.host_cp0_cause;
u32 exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
u32 __user *opc = (u32 __user *) vcpu->arch.pc;
2 changes: 1 addition & 1 deletion arch/mips/kvm/trap_emul.c
Original file line number Diff line number Diff line change
@@ -1241,7 +1241,7 @@ static int kvm_trap_emul_vcpu_run(struct kvm_vcpu *vcpu)
*/
kvm_mips_suspend_mm(cpu);

r = vcpu->arch.vcpu_run(vcpu->run, vcpu);
r = vcpu->arch.vcpu_run(vcpu);

/* We may have migrated while handling guest exits */
cpu = smp_processor_id();
2 changes: 1 addition & 1 deletion arch/mips/kvm/vz.c
Original file line number Diff line number Diff line change
@@ -3266,7 +3266,7 @@ static int kvm_vz_vcpu_run(struct kvm_vcpu *vcpu)
kvm_vz_vcpu_load_tlb(vcpu, cpu);
kvm_vz_vcpu_load_wired(vcpu);

r = vcpu->arch.vcpu_run(vcpu->run, vcpu);
r = vcpu->arch.vcpu_run(vcpu);

kvm_vz_vcpu_save_wired(vcpu);

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