MIPS: KVM: Override guest kernel timer frequency directly (eda3d33c) · Commits · 戴 / test

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>

arch/mips/Kconfig

+6 −6

Original line number	Diff line number	Diff line
		@@ -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"

arch/mips/mti-malta/malta-time.c

+2 −12

Original line number	Diff line number	Diff line
		@@ -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

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