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| author | AKASHI Takahiro <takahiro.akashi@linaro.org> | 2016-04-27 17:47:05 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2016-04-28 12:05:46 +0100 |
| commit | 67f6919766620e7ea7aab11a6a3470dc7b451359 (patch) | |
| tree | 603439d01bc9ecb8e8d7f0abda6b5a1bed2394e4 /arch/arm64/kvm | |
| parent | c94b0cf28281d483c8b43b4874fcb7ab14ade1b1 (diff) | |
| download | linux-67f6919766620e7ea7aab11a6a3470dc7b451359.tar.gz linux-67f6919766620e7ea7aab11a6a3470dc7b451359.tar.bz2 linux-67f6919766620e7ea7aab11a6a3470dc7b451359.zip | |
arm64: kvm: allows kvm cpu hotplug
The current kvm implementation on arm64 does cpu-specific initialization
at system boot, and has no way to gracefully shutdown a core in terms of
kvm. This prevents kexec from rebooting the system at EL2.
This patch adds a cpu tear-down function and also puts an existing cpu-init
code into a separate function, kvm_arch_hardware_disable() and
kvm_arch_hardware_enable() respectively.
We don't need the arm64 specific cpu hotplug hook any more.
Since this patch modifies common code between arm and arm64, one stub
definition, __cpu_reset_hyp_mode(), is added on arm side to avoid
compilation errors.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
[Rebase, added separate VHE init/exit path, changed resets use of
kvm_call_hyp() to the __version, en/disabled hardware in init_subsystems(),
added icache maintenance to __kvm_hyp_reset() and removed lr restore, removed
guest-enter after teardown handling]
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kvm')
| -rw-r--r-- | arch/arm64/kvm/hyp-init.S | 38 | ||||
| -rw-r--r-- | arch/arm64/kvm/reset.c | 14 |
2 files changed, 52 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S index 5ce1b47ef770..44ec4cb23ae7 100644 --- a/arch/arm64/kvm/hyp-init.S +++ b/arch/arm64/kvm/hyp-init.S @@ -139,6 +139,44 @@ merged: eret ENDPROC(__kvm_hyp_init) + /* + * x0: HYP boot pgd + * x1: HYP phys_idmap_start + */ +ENTRY(__kvm_hyp_reset) + /* We're in trampoline code in VA, switch back to boot page tables */ + msr ttbr0_el2, x0 + isb + + /* Ensure the PA branch doesn't find a stale tlb entry or stale code. */ + ic iallu + tlbi alle2 + dsb sy + isb + + /* Branch into PA space */ + adr x0, 1f + bfi x1, x0, #0, #PAGE_SHIFT + br x1 + + /* We're now in idmap, disable MMU */ +1: mrs x0, sctlr_el2 + ldr x1, =SCTLR_ELx_FLAGS + bic x0, x0, x1 // Clear SCTL_M and etc + msr sctlr_el2, x0 + isb + + /* Invalidate the old TLBs */ + tlbi alle2 + dsb sy + + /* Install stub vectors */ + adr_l x0, __hyp_stub_vectors + msr vbar_el2, x0 + + eret +ENDPROC(__kvm_hyp_reset) + .ltorg .popsection diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 9677bf069bcc..4062e6dd4cc1 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -29,7 +29,9 @@ #include <asm/cputype.h> #include <asm/ptrace.h> #include <asm/kvm_arm.h> +#include <asm/kvm_asm.h> #include <asm/kvm_coproc.h> +#include <asm/kvm_mmu.h> /* * ARMv8 Reset Values @@ -130,3 +132,15 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) /* Reset timer */ return kvm_timer_vcpu_reset(vcpu, cpu_vtimer_irq); } + +extern char __hyp_idmap_text_start[]; + +phys_addr_t kvm_hyp_reset_entry(void) +{ + unsigned long offset; + + offset = (unsigned long)__kvm_hyp_reset + - ((unsigned long)__hyp_idmap_text_start & PAGE_MASK); + + return TRAMPOLINE_VA + offset; +} |