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authorJames Hogan <james.hogan@imgtec.com>2014-05-29 10:16:36 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2014-05-30 13:02:23 +0200
commiteda3d33c685ff62524500681249e4c8e2e8dbb8c (patch)
tree179621cdccda7d859e99c37e469cb939dc22e453 /arch
parente30492bbe95a2495930aa7db7eacde5141e45332 (diff)
MIPS: KVM: Override guest kernel timer frequency directly
The KVM_HOST_FREQ Kconfig symbol was used by KVM guest kernels to override the timer frequency calculation to a value based on the host frequency. Now that the KVM timer emulation is implemented independent of the host timer frequency and defaults to 100MHz, adjust the working of CONFIG_KVM_HOST_FREQ to match. The Kconfig symbol now specifies the guest timer frequency directly, and has been renamed accordingly to KVM_GUEST_TIMER_FREQ. It now defaults to 100MHz too and the help text is updated to make it clear that a zero value will allow the normal timer frequency calculation to take place (based on the emulated RTC). Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: Sanjay Lal <sanjayl@kymasys.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/Kconfig12
-rw-r--r--arch/mips/mti-malta/malta-time.c14
2 files changed, 8 insertions, 18 deletions
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 5cd695f905a1..5e0014e864f3 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1756,14 +1756,14 @@ config KVM_GUEST
help
Select this option if building a guest kernel for KVM (Trap & Emulate) mode
-config KVM_HOST_FREQ
- int "KVM Host Processor Frequency (MHz)"
+config KVM_GUEST_TIMER_FREQ
+ int "Count/Compare Timer Frequency (MHz)"
depends on KVM_GUEST
- default 500
+ default 100
help
- Select this option if building a guest kernel for KVM to skip
- RTC emulation when determining guest CPU Frequency. Instead, the guest
- processor frequency is automatically derived from the host frequency.
+ Set this to non-zero if building a guest kernel for KVM to skip RTC
+ emulation when determining guest CPU Frequency. Instead, the guest's
+ timer frequency is specified directly.
choice
prompt "Kernel page size"
diff --git a/arch/mips/mti-malta/malta-time.c b/arch/mips/mti-malta/malta-time.c
index 319009912142..3778a359f3ad 100644
--- a/arch/mips/mti-malta/malta-time.c
+++ b/arch/mips/mti-malta/malta-time.c
@@ -74,18 +74,8 @@ static void __init estimate_frequencies(void)
unsigned int giccount = 0, gicstart = 0;
#endif
-#if defined (CONFIG_KVM_GUEST) && defined (CONFIG_KVM_HOST_FREQ)
- unsigned int prid = read_c0_prid() & (PRID_COMP_MASK | PRID_IMP_MASK);
-
- /*
- * XXXKYMA: hardwire the CPU frequency to Host Freq/4
- */
- count = (CONFIG_KVM_HOST_FREQ * 1000000) >> 3;
- if ((prid != (PRID_COMP_MIPS | PRID_IMP_20KC)) &&
- (prid != (PRID_COMP_MIPS | PRID_IMP_25KF)))
- count *= 2;
-
- mips_hpt_frequency = count;
+#if defined(CONFIG_KVM_GUEST) && CONFIG_KVM_GUEST_TIMER_FREQ
+ mips_hpt_frequency = CONFIG_KVM_GUEST_TIMER_FREQ * 1000000;
return;
#endif