On 2020/9/30 15:52, Hanjun Guo wrote:

On 2020/9/30 15:29, Yang Yingliang wrote:

...

This reverts commit 8cc25436c41592b2236b4d2911a3031131a62872.

Why? and missing SOB.

I have add the SOB, when push the code.

Is this fixing the kvm compile error issue?

The stable patch used kvm_host_cpu_state that is removed by

80bda31c7d60 ("arm64: KVM: Encapsulate kvm_cpu_context in kvm_host_data").

We using kvm_host_data instead in patch #2, keep it same as mainline.

Thanks Hanjun

...

---

arch/arm64/include/asm/kvm_asm.h | 15 ----------   arch/arm64/kernel/vmlinux.lds.S  |  8 -----   arch/arm64/kvm/hyp/entry.S       | 16 ++++------   arch/arm64/kvm/hyp/hyp-entry.S   | 51 +++++++++++++-------------------   arch/arm64/kvm/hyp/switch.c      | 31 -------------------   5 files changed, 26 insertions(+), 95 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 5df55a4dab42..400cb2af5ba6 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -146,21 +146,6 @@ extern u32 __kvm_get_mdcr_el2(void);       kern_hyp_va    \vcpu   .endm   -/*

• • KVM extable for unexpected exceptions.
• • In the same format _asm_extable, but output to a different

section so that

• • it can be mapped to EL2. The KVM version is not sorted. The

caller must

• • ensure:
• • x18 has the hypervisor value to allow any Shadow-Call-Stack

instrumented

• • code to write to it, and that SPSR_EL2 and ELR_EL2 are restored

by the fixup.

• */

-.macro    _kvm_extable, from, to -    .pushsection    __kvm_ex_table, "a" -    .align        3 -    .long        (\from - .), (\to - .) -    .popsection -.endm

#endif     #endif /* __ARM_KVM_ASM_H__ */ diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index 69e7c8d4a00f..d6050c6e65bc 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -24,13 +24,6 @@ ENTRY(_text)     jiffies = jiffies_64;   - -#define HYPERVISOR_EXTABLE                    \ -    . = ALIGN(SZ_8);                    \ -    __start___kvm_ex_table = .;                \ -    *(__kvm_ex_table)                    \ -    __stop___kvm_ex_table = .;

#define HYPERVISOR_TEXT                    \       /*                        \        * Align to 4 KB so that            \ @@ -46,7 +39,6 @@ jiffies = jiffies_64;       __hyp_idmap_text_end = .;            \       __hyp_text_start = .;                \       *(.hyp.text)                    \ -    HYPERVISOR_EXTABLE                \       __hyp_text_end = .;     #define IDMAP_TEXT                    \ diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index 90e012fa3ca5..a0552b5177c5 100644 --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -164,22 +164,18 @@ alternative_endif       // This is our single instruction exception window. A pending       // SError is guaranteed to occur at the earliest when we unmask       // it, and at the latest just after the ISB. +    .global    abort_guest_exit_start   abort_guest_exit_start:         isb   +    .global    abort_guest_exit_end   abort_guest_exit_end: -    msr    daifset, #4    // Mask aborts -    ret

-    _kvm_extable    abort_guest_exit_start, 9997f -    _kvm_extable    abort_guest_exit_end, 9997f -9997: -    msr    daifset, #4    // Mask aborts -    mov    x0, #(1 << ARM_EXIT_WITH_SERROR_BIT)   -    // restore the EL1 exception context so that we can report some -    // information. Merge the exception code with the SError pending bit. +    // If the exception took place, restore the EL1 exception +    // context so that we can report some information. +    // Merge the exception code with the SError pending bit. +    tbz    x0, #ARM_EXIT_WITH_SERROR_BIT, 1f       msr    elr_el2, x2       msr    esr_el2, x3       msr    spsr_el2, x4 diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index c3e4ae84f3a4..71591a6ee63e 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -26,30 +26,6 @@   #include <asm/kvm_mmu.h>   #include <asm/mmu.h>   -.macro save_caller_saved_regs_vect -    /* x0 and x1 were saved in the vector entry */ -    stp    x2, x3,   [sp, #-16]! -    stp    x4, x5,   [sp, #-16]! -    stp    x6, x7,   [sp, #-16]! -    stp    x8, x9,   [sp, #-16]! -    stp    x10, x11, [sp, #-16]! -    stp    x12, x13, [sp, #-16]! -    stp    x14, x15, [sp, #-16]! -    stp    x16, x17, [sp, #-16]! -.endm

-.macro restore_caller_saved_regs_vect -    ldp    x16, x17, [sp], #16 -    ldp    x14, x15, [sp], #16 -    ldp    x12, x13, [sp], #16 -    ldp    x10, x11, [sp], #16 -    ldp    x8, x9,   [sp], #16 -    ldp    x6, x7,   [sp], #16 -    ldp    x4, x5,   [sp], #16 -    ldp    x2, x3,   [sp], #16 -    ldp    x0, x1,   [sp], #16 -.endm

.text       .pushsection    .hyp.text, "ax"   @@ -209,14 +185,27 @@ el2_sync:       el2_error: -    save_caller_saved_regs_vect -    stp     x29, x30, [sp, #-16]!

-    bl    kvm_unexpected_el2_exception

-    ldp     x29, x30, [sp], #16 -    restore_caller_saved_regs_vect +    ldp    x0, x1, [sp], #16   +    /* +     * Only two possibilities: +     * 1) Either we come from the exit path, having just unmasked +     *    PSTATE.A: change the return code to an EL2 fault, and +     *    carry on, as we're already in a sane state to handle it. +     * 2) Or we come from anywhere else, and that's a bug: we panic. +     * +     * For (1), x0 contains the original return code and x1 doesn't +     * contain anything meaningful at that stage. We can reuse them +     * as temp registers. +     * For (2), who cares? +     */ +    mrs    x0, elr_el2 +    adr    x1, abort_guest_exit_start +    cmp    x0, x1 +    adr    x1, abort_guest_exit_end +    ccmp    x0, x1, #4, ne +    b.ne    __hyp_panic +    mov    x0, #(1 << ARM_EXIT_WITH_SERROR_BIT)       eret       sb   diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index e9ea7cf3e98f..acd2d84b190c 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -25,7 +25,6 @@     #include <asm/barrier.h>   #include <asm/cpufeature.h> -#include <asm/extable.h>   #include <asm/kprobes.h>   #include <asm/kvm_asm.h>   #include <asm/kvm_emulate.h> @@ -37,9 +36,6 @@   #include <asm/processor.h>   #include <asm/thread_info.h>   -extern struct exception_table_entry __start___kvm_ex_table; -extern struct exception_table_entry __stop___kvm_ex_table;

/* Check whether the FP regs were dirtied while in the host-side run loop: */   static bool __hyp_text update_fp_enabled(struct kvm_vcpu *vcpu)   { @@ -730,30 +726,3 @@ void __hyp_text __noreturn hyp_panic(struct kvm_cpu_context *host_ctxt)         unreachable();   }

-asmlinkage void __hyp_text kvm_unexpected_el2_exception(void) -{ -    unsigned long addr, fixup; -    struct kvm_cpu_context *host_ctxt; -    struct exception_table_entry *entry, *end; -    unsigned long elr_el2 = read_sysreg(elr_el2);

-    entry = hyp_symbol_addr(__start___kvm_ex_table); -    end = hyp_symbol_addr(__stop___kvm_ex_table); -    host_ctxt = __hyp_this_cpu_ptr(kvm_host_cpu_state);

-    while (entry < end) { -        addr = (unsigned long)&entry->insn + entry->insn; -        fixup = (unsigned long)&entry->fixup + entry->fixup;

-        if (addr != elr_el2) { -            entry++; -            continue; -        }

-        write_sysreg(fixup, elr_el2); -        return; -    }

-    hyp_panic(host_ctxt); -}

.