From 56e62a73702836017564eaacd5212e4d0fa1c01d Mon Sep 17 00:00:00 2001 From: Sven Schnelle Date: Sat, 21 Nov 2020 11:14:56 +0100 Subject: s390: convert to generic entry This patch converts s390 to use the generic entry infrastructure from kernel/entry/*. There are a few special things on s390: - PIF_PER_TRAP is moved to TIF_PER_TRAP as the generic code doesn't know about our PIF flags in exit_to_user_mode_loop(). - The old code had several ways to restart syscalls: a) PIF_SYSCALL_RESTART, which was only set during execve to force a restart after upgrading a process (usually qemu-kvm) to pgste page table extensions. b) PIF_SYSCALL, which is set by do_signal() to indicate that the current syscall should be restarted. This is changed so that do_signal() now also uses PIF_SYSCALL_RESTART. Continuing to use PIF_SYSCALL doesn't work with the generic code, and changing it to PIF_SYSCALL_RESTART makes PIF_SYSCALL and PIF_SYSCALL_RESTART more unique. - On s390 calling sys_sigreturn or sys_rt_sigreturn is implemented by executing a svc instruction on the process stack which causes a fault. While handling that fault the fault code sets PIF_SYSCALL to hand over processing to the syscall code on exit to usermode. The patch introduces PIF_SYSCALL_RET_SET, which is set if ptrace sets a return value for a syscall. The s390x ptrace ABI uses r2 both for the syscall number and return value, so ptrace cannot set the syscall number + return value at the same time. The flag makes handling that a bit easier. do_syscall() will just skip executing the syscall if PIF_SYSCALL_RET_SET is set. CONFIG_DEBUG_ASCE was removd in favour of the generic CONFIG_DEBUG_ENTRY. CR1/7/13 will be checked both on kernel entry and exit to contain the correct asces. Signed-off-by: Sven Schnelle Signed-off-by: Vasily Gorbik --- arch/s390/kvm/kvm-s390.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/s390/kvm/kvm-s390.c') diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index dbafd057ca6a..759bbc012b6c 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -45,6 +45,7 @@ #include #include #include +#include #include "kvm-s390.h" #include "gaccess.h" @@ -4147,6 +4148,8 @@ static int __vcpu_run(struct kvm_vcpu *vcpu) vcpu->run->s.regs.gprs, sizeof(sie_page->pv_grregs)); } + if (test_cpu_flag(CIF_FPU)) + load_fpu_regs(); exit_reason = sie64a(vcpu->arch.sie_block, vcpu->run->s.regs.gprs); if (kvm_s390_pv_cpu_is_protected(vcpu)) { -- cgit v1.2.3